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No. 106 MAY 1971 



RESOURCE MANAGEMENT REPORT 



x^ v3Ib/ ^* 




ONTARIO 




DEPARTMENT OF LANDS AND FORESTS 




HON. RENE BRUNELLE 


W. Q. MACNEE 


Minister 


Deputy Minister 



No. 106 MAY 1971 



RESOURCE MANAGEMENT REPORT 



FISH AND WILDLIFE BRANCH 







ONTARIO 




DEPARTMENT OF LANDS AND FORESTS 




HON. RENE BRUNELLE 


W. Q. MACNEE 


Minister 


Deputy Minister 



PREFACE 



Recently, the Resource Management Report has not 
only been one year behind its year of publication, but 
the reports included in it have also been somewhat out- 
dated. Therefore, in an attempt to rectify this situ- 
ation, this issue is dated May, 1971, but the numbering 
remains continuous (#106). In future issues, the 
material published will be as current as possible. 



The Editor 



ARY 



Digitized by the Internet Archive 

in 2013 



http://archive.org/details/resourcemanmay1971onta 



RESOURCE MANAGEMENT REPORT 
TABLE OF CONTENTS 

No. 106 ^7 * 971 

Page 

AN OBJECTIVE ASSESSMENT OF THE SPLAKE AS A MANAGEMENT TOOL 

FOR ONTARIO'S INLAND WATERS 1 

- M. L. Wilton 



A COMPARISON OF THREE METHODS USED TO DETERMINE THE AGE OF 
WHITE -TAILED DEER 

- W. D„ Mansell 

- D. N. Meeking 



AN ALTERNATE METHOD OF ASSESSING SNOW QUALITY 15 

■ S. A. Munroe 



A STUDY OF MOOSE BROWSING AND POPULATION DECLINE ON TWO ISLANDS 
OF LAKE NIPIGON 21 

- B. Ho Gibson 



THE LAKE STURGEON ( Acipenser fulvescens ) OF LAKE NIPISSING-- 

A PRELIMINARY REPORT ^0 

- J . K „ Young 

- G, Fo Love 



REPRODUCTIVE CHARACTERISTICS OF THE PARRY SOUND DEER HERD 61 

- S . A . Munroe 



AN OBJECTIVE ASSESSMENT OF THE SPIAKE AS 
A MANAGEMENT TOOL FOR 
ONTARIO'S INLAND WATERS 

by 

M. L. WILTON, Biologist 
Pembroke District 



INTRODUCTION 

Since the commencement of the Lake Huron rehabilitation program, 
the hybrid of the eastern brook trout ( Salvelinus fontinalis ) and the lake trout 
( Salvelinus namaycush ) , commonly known as the splake or wendigo, has gained a 
place of prominence as a potential inland water game fish. Before a realistic 
and biologically sound policy could be developed for this hybrid, it was deemed 
advisable to summarize and subsequently analyse as many of the facts relating 
to the splake as could be obtained. 

This report consists of a review of pertinent literature, a 
summary of discussions with field workers, and finally, conclusions and recom- 
mendations relating to the future of splake in inland waters. 

Since a significant proportion of the data contained herein has 

not as yet been published, but likely shall be, it is requested that the contents 

of this submission be regarded as confidential and be retained for intra- 
Departmental use only. 

LITERATURE REVIEW 

A rather complete review of the literature pertaining to splake 
was possible through the use of a bibliography prepared in 1960 by Mr. N. V. 
Martin of the Research Branch. This bibliography has since been up-dated by 
Mr. A. H. Berst, also of the Research Branch. In all, nineteen of the available 
reference works were consulted, of which it was felt that eight contained signifi- 
cant contributions to a study of this sort. 

There follows a short chronological summary of what were con- 
sidered to be the relevant facts contained in these eight reference papers. 

1952 Pearson, Beverly E. The behaviour of a sample of hybrid trout 

( Salvelinus fontinalis x Cristwomer namaycush ) in a vertical 
temperature for gradient. 
- Preferred temperature for splake is 12° C. 



1952 Solman, V. E. F., J. P. Cuerrier, and W. C. Cable. Why have 

fish hatcheries in Canada's National Parks? Trans, of the 
Seventeenth North American Wildlife Conference „ 

- Splake grow faster and are better acclimated to cold water 
than eastern brook trout. 

- Splake are more easily taken on a fly than lake trout, 

1958-59 Leik, Thomas H. An evaluation of the splake trout--downstream 

migration studies. Colorado Co-operative Fisheries Research 
Unit. Colorado A and M College Quarterly Report, Vol. 5. 

- 10,000 splake and 15,000 rainbow trout were planted in 
Parvin Lake, Colorado, in June of 1958. 

- Of 122 fish trapped during downstream migration, splake 
represented 90% and rainbows only 10%. 

- 75% of migration occurred within 30 days of planting. 

I960 Martin, N, V. and N. S. Baldwin. Observations on the life 

history of the hybrid between eastern brook trout and lake 
trout in Algonquin Park, Ontario. J. Fish Res. Bd . Canada 17 
(4). 

- With the exception of Jack Lake, recoveries of hybrids have 
been less than 2% of the fish stocked. 

- Recovery from the first planting of 700 hybrids in Jack Lake 
in 1954 was remarkably high with anglers taking 65% in 1956 
and 1957. 

- In general, when mixed plantings of marked lake trout, brook 
trout and hybrids have been made, the recovery of hybrids has 
been higher. 

- Generally most hybrids are found between the 8° and 20° C 
isotherms during stratification, whereas brook trout are more 
likely to be found between the 12° and 20° C isotherms and 
lake trout in water which is colder than 14° C. This would 
indicate that the preferred temperature of the hybrid is 
closer to that of the brook trout which is the reverse of 
laboratory studies (Pearson, 1952) . 

- Generally, the hybrid trout appear to have a more rapid growth 
rate than brook trout or lake trout. 

- Almost all hybrids were mature at age III in Jack Lake. 

- Hybrids were observed spawning on rocky shoals in early 
November and had spawning characteristics of each parent . 

- Eggs deposited in Jack Lake had hatched by April 28, indicating 
an incubation period of about 6 months. 

- In angling, depth distribution, food, maturity, fecundity, and 
time and duration of spawning the hybrid trout is closer to 
the brook trout than the lake trout. 

- Length-weight relationship and place of successful spawning 
are more similar to the lake trout. 

- The hybrids grow faster than either parent and school more 
strongly . 

1962 Burkhard, Walter T. A study of the splake trout in Parvin Lake, 

Colorado. Unpublished Master of Science Thesis, Colorado State 
University . 

- Splake fed predominantly on small crustaceans throughout the 
year with insects being important only during the spring and 
fall. 



- Splake preferred water temperatures near 54° F. 

- The majority of splake matured in the third year of life and 
spawned in water depths of 6 to 12 feet along the rip-rap of 
the dams . 

- No natural spawning success was observed. 

- No migration out of the lake was noted except for a limited 
period immediately after introduction into the lake. (Leik, 
1958-59). 

- The incidence of fish as a diet item increased as the size of 
the splake increased. 

1964 Boles, Hallett D, and Frederick A. Meyer. Splake in Deer and 
Lower Salmon Lakes, Sierra County, Inl . Fish. Adm. Rep. Calif., 
64-6:1-7. 

- Creel census carried out in two California lakes after splake 
introduction concluded that splake are not suitable for this 
type of management. 

- Poor access to one lake with consequent low angling pressure 
and shallow depth of the other lake with probable poor survival 
could not offset the high cost of artificial rearing, since no 
apparent outstanding contribution was made to the fisheries. 

1965 Martin, N. V. Wendigo— The Not-So-Evil Spirit. Ont . Fish and 
Wildlife Review, Vol. 4, No. 3, pp. 12-18. 

- Excellent game fish, most frequently fighting like the brook 
trout, but occasionally diving deep like the lake trout. 

- Appear to be more vulnerable to fly fishing than the brook 
trout or lake trout . 

- Seems to be a tendency to "school." 

- By and large, appears to be more vulnerable to angling than 
either brook or lake trout . 

- Frequent depths of 20-35 feet and water temperatures of 50- 
70° F during summer stratification period. 

- While lake trout are primarily piscivorous, wendigo more 
closely resemble feeding habits of brook trout, feeding mainly 
on mayflies, leeches, frogs, salamanders, and plankton. 

- Appear to have a more rapid growth rate than either parent . 

- Have lived in nature for as long as 9 years--as against 6 
years maximum for brook trout. 

- Maximum size is as yet unknown, although in 1960 a 16 lb. 
wendigo was taken in a Northern Ontario lake. 

- Most wendigo appear to be mature at age 3--most brook trout 
are mature by age 3 whereas most lake trout are mature by age 
6 or 7 , 

- Appear to prefer gravelly areas for spawning, as do the brook 
trout, but will spawn on rocky slopes as do the. lake trout, if 
no gravelly areas available. 

1970 Berst, A. H. and G. R. Spangler. Population dynamics of F^ 

splake, Salve linus font ina lis x S . namaycush in Lake Huron. 
Unpublished manuscript, Ont. Dept . of Lands and Forests, Research 
Branch . 

- Growth rates of hybrids in Lake Huron exceeded those reported 
for native and planted lake trout, 



- Yearlings fed mainly on invertebrates while 2 to 4 year olds 
fed almost entirely on fish, 

- By age 3, the majority of hybrids had reached maturity, and 
some ripe individuals were captured over former lake trout 
spawning beds , 



SUMMARY OF DISCUSSIONS WITH PERSONNEL 

The names and classifications of persons interviewed are sum- 
marized alphabetically in "Appendix I," I wish to express my sincerest thanks 
to all those people who, without exception, willingly discussed at length their 
experiences with splake. I would consider it unwise to single out individuals 
who made outstanding contributions since it is my desire to present this material 
in as unbiased a way as possible. 

Discussions were held in an informal fashion with categorical 
questions occasionally being asked by the interviewer in order that the person 
or persons being interviewed could be prompted to present their most complete 
understanding of the splake and its environments 

Following is a list of the major categorical questions and 
summaries of the various opinions expressed: 

1. Do you feel that there is a place for splake in Ontario's inland waters? 

Without exception all those people who have worked with splake 
feel that this fish has sufficient attributes to make it a 
worthwhile addition to Ontario's inland fisheries. The majority 
of people questioned also expressed the belief that this fish 
is not a "cure-all" and that restraint should be exercised 
regarding the number and location of planting sites. 

2. Are splake able to compete with other species? 

Little evidence has been documented in this regard. While 
there is widespread belief that splake are probably better able 
to withstand competition than brook trout, generally speaking 
it would appear that the numerous low returns from splake 
planted in lakes with resident species probably result from 
competition. 

Returns would appear to vary directly with the severity of 
competition according to the following scale: 



barren 



barren 
minnows 



excellent good 



barren 

minnows 

suckers 



fair 



barren 
minnows 
suckers 
spiny rayed 

poor 



barren 

minnows 

suckers 

spiny rayed 

pike 

nil 



3. How do growth rates compare? 

It has been adequately demonstrated that splake will normally 
far surpass the annual growth attained by lake trout. Most 
workers feel that splake will at least equal and in a majority 
of cases also exceed the annual growth of brook trout . Perhaps 
this is indeed an instance of "hybrid vigor." It should also 
be mentioned that since the life expectancy of splake is prob- 
ably close to double that of brook trout, maximum attainable 
size is likely proportionately greater. 

4. What part could natural reproduction play in the future of this hybrid? 

Natural reproduction is known to have occurred only twice in 
Ontario to date; in Jack Lake, Algonquin Park, and in Lake 
No. 17, Sudbury Forest District. 

Workers generally feel that splake will seek out the gravel 
seepage shoals preferred by brook trout, but in the absence of 
these will spawn on rocky shoals similar to those favoured by 
lake trout. It appears as well that splake spawn generally 
later than lake trout, more coincident with the brook trout 
spawning period. 

This potential spawning diversity presumably enables the splake 
to better adapt itself than either parent to marginal water, 
although this has not as yet been adequately demonstrated. 

5. Are splake mainly sedentary or is migration common? 

While migration does not appear to be common, downstream 
migration has been observed in Sault Ste. Marie District and 
Algonquin Park, and upstream migration has been observed on 
Manitoulin Island. 

6. Would a province wide splake planting program be economically feasible? 

While some workers feel that splake can be more economically 
produced from our hatcheries than either parent, it would appear 
that costs are intermediate between both parents, but more 
closely approximate those of the brook trout. Generally 
speaking then, it would appear that splake can be produced at 
slightly higher cost than brook trout, but at substantially 
lower cost than lake trout . 

Since it appears that the growth rate "in nature" exceeds that 
of either parent, then the splake is indeed economically feasi- 
ble from both the yield per unit area and trophy fish stand- 
point . 

7. Are anglers willing to accept splake as a bona fide game fish? 

Without exception., all persons contacted felt that anglers have 
a very high opinion of splake not only from a catchability 
standpoint but because of its fighting and eating qualities 
and general appearance as well. 



8. What is your opinion regarding the stocking of splake in waters with native 
species present? 

It was the opinion of most persons interviewed that if a lake 
is supporting or is capable of supporting a healthy population 
of either brook or lake trout, these native species should be 
retained. 

There is a distinct possibility that the planting of splake, 
particularly in self-sustaining lake trout waters, could even- 
tually lead to back crosses with subsequent loss of species 
individuality, 

9. Would you describe what you feel is the ideal splake lake? 

In general most persons interviewed felt that the splake is 
best suited to an intermediate type of lake which lies somewhere 
between the ideal brook trout "pot hole" and the typical "big 
water" lake trout lake. 

This intermediate type of lake could probably best be described 
as follows: 

- Between 50 and 200 acres surface area. 

- Maximum depth 40-80 feet . 

- Clear water--secchi disc 20 feet. 

- Shoreline ranging from gravel to boulder shoals preferably 
with seepage. 

- Small littoral zone--steep basin shape. 

- Minimal outflow. 

- Barren of other fish species. 

COMPARISON OF THREE SUCCESSFUL SPLAKE LAKES 

While discussions with field personnel indicated that varying 
degrees of success had been reached with splake plantings throughout the pro- 
vince, three lakes stood out as having yielded notable results. Indeed the 
personnel concerned did not hesitate to classify these as "ideal splake lakes." 
For this reason it was decided to include some pertinent facts about these 
lakes in this report so that a better understanding of the "optimum splake 
environment" may be obtained. 

Lake # 17* 

Area (acres) 142 

Max. depth (feet) 80 

pH 6.2 

Secchi disc (feet) 

Tot. alkalinity 35 ppm. 

T.D.S. 

Other Species Cyprinids 

Sticklebacks 



Jack Lake** 


Mace Lake*** 


55 




358 


60 




45 


— 




7.0 


21 




13 


— 




16 ppm 


32 


ppm 


44 ppm 


Sticklebacks 


brook trout 






dace 



suckers (2 spp) 



* Sudbury District 
** Algonquin Park (Pembroke District) 
*** Sault Ste. Marie District 



It should be noted that natural reproduction is known to have 
taken place in Jack Lake (Martin and Baldwin, 1960) and Lake #17 (Berst and 
Hughson, personal communication), but has not been demonstrated in Mace Lake. 

While Lake #17 and Jack Lake fall within the definition of what 
most field personnel feel to be "ideal splake water," Mace Lake on the other 
hand has almost twice the recommended surface area. This serves to point up 
the necessity of allowing field personnel a certain degree of freedom in deciding 
which lakes shall be planted with splake--for only in this way will the true 
parameters be established. 

SUMMARY OF FINDINGS 

The following definition summarizes the facts learned about the 
splake and its preferred environment during this study. 

The Splake and its Environment : The splake, or wendigo, is the 
colourful offspring of the female lake trout and the male brook trout. Its 
appearance generally is midway between that of the brook trout and lake trout, 
with a moderately forked caudal fin, and side spots which are less bright than 
those of the brook trout, tending to a pale pink or mauve. 

Unlike many hybrids, the splake is able to reproduce and while 
it prefers the gravel seepage shoals usually used by brook trout for lake spawning, 
in the absence of these it will use the boulder shoals favoured by lake trout. 
Splake are usually mature in their third year of life and their spawning period 
falls closer to that of the brook trout in late October or early November. 

Splake prefer barren, clear water, medium sized lakes ranging 
from 50 to 200 acres in size with maximum depths of from 40 to 80 feet. They 
will usually be found in the thermocline during the summer stratification period 
as they prefer a temperature in the vicinity of 54° F. 

The hybrid has a more rapid growth rate than either parent and 
a longer life span than the brook trout. It feeds heavily on crustaceans and 
insects during early life and gradually becomes more piscivorous as size increases. 

Splake have a strong tendancy to school which often gives rise 
to short periods of intensive angling success. They are excellent fighters, 
with flesh which is pink through orange in colour and is highly regarded for 
its eating qualities. 

RECOMMENDATIONS 

Since the majority of persons who have worked with the splake 
feel that it is potentially a beneficial management tool, if properly controlled, 
and since it appears that there is a specific class of waters which is best 
suited to the production of splake, the following procedure is recommended: 

1. That provisions be made through the Hatcheries 
Section to produce between 100,000 and 200,000 
yearling splake for the planting of inland 
waters for a period of 10 years, and distribute 

them annually to those Forest Districts so 
requesting. 



APPENDIX I 



That a directive be issued from Main Office 
outlining major facts concerning the splake 
and its environment which may be helpful to 
district personnel in planning their stock- 
ing programs . 

That at the end of the ten year period, an 
assessment program be carried out and splake 
production adjusted accordingly. 



PERSONS INTERVIEWED CONCERNING SPIAKE 



NAME 



CLASSIFICATION 



Bailey, R. G. 
Berst, A. H. 
Campbell, R. 
Chambers, K. C. 
Fraser, J. M. 
Holder, A. S. 
Hugh son, D. R. 
Martin, N. V. 
McDonald, P. 
McKeown , W . 
Neunan, P. 
Olver, C. H. 
Payne , R . 
Stassen, G. M. 
Straight, W. J. 
Tait, J. S. 
von Rosen, H.* 
Weir, J. C. 
Wohlgemuth, 0. 
Wolfe, M. R. 
Woodside, S. B. 



Biologist, Sault Ste. Marie District 
Biologist, Research Branch 
Conservation Officer, North Bay District 
Biologist, Fish and Wildlife Branch 
Biologist, Research Branch 
Biologist, North Bay District 
Conservation Officer, Sudbury District 
Biologist, Research Branch 
Conservation Officer, Kenora District 
Conservation Officer, North Bay District 
Biologist, Thunder Bay District 
Biologist, Sault Ste. Marie District 
Biologist, Fish and Wildlife Branch 
Biologist, Sudbury 

Biologist, Fish and Wildlife Branch 
Professor, York University 
Conservation Officer, Tweed District 
Biologist, Fish and Wildlife Branch 
Conservation Officer, Sault Ste. Marie 
Biologist, Cochrane District 
Conservation Officer, Lake Huron District 



Written communication 



A COMPARISON OF THREE METHODS USED 
TO DETERMINE THE AGE OF WHITE -TAILED DEER 

by 

W. D. MANSELL, Fish and Wildlife Supervisor 
D. N. MEEKING, Biologist 
Lake Huron District 



ABSTRACT 



Two relatively new techniques for determining 
the age of deer are evaluated with relation to 
tooth-erosion ages. In a sample of 53 jaws in which 
erosion and incisor-sectioning were compared, the 
mean age was 2.91 years and 3.33 years respectively. 
Only one yearling and 11 adults were aged differ- 
ently using these two methods. In a sample of 192 
jaws the mean age as determined by the erosion 
method was 2.30 years while for the incisor- 
grinding method it was 2.53 years. One fawn, nine 
yearlings and 26 adults were aged incorrectly. A 
trend of increasing error in assigning age was 
noted when wear-classes were compared with count 
of cemental annuli. Our data are inconclusive 
because our initial assumption that wear-classes 
represent the accurate age is false. One can 
only suspect the accuracy of determining wear- 
classes. The comparative effort for 100 samples 
of the tooth-erosion, incisor-sectioning and 
incisor-grinding techniques was 2, 65 and 14 man- 
hours respectively. 



INTRODUCTION 

The tooth-erosion method (Severinghaus 1949) of determining ages 
of white-tailed deer has been an accepted technique for many years. It is 
practical to use and provides immediate estimates of age. However, the wear- 
class method does not take into account such variations in tooth quality as 
occurs between races of deer or between rates of wear as a result of variations 
in habitat and browse utilized. 

Sergeant and Pimlott (1959) were the first authors to attempt 
age determination in cervids based on the cemental annuli of the first incisor. 
Recent work with white-tailed deer suggests that cemental annuli in the incisors 
(Gilbert 1966) and in the molars (Ransom 1966) is useful in establishing age. 
Both previous methods require a great deal of time in decalcifying and staining 
sections of the teeth before age can be determined. 



A simplified and quicker method of preparing incisors for age 
determination has been developed by Simkin (1967) for moose. The technique is 
based upon the identification of cemental annuli exposed by grinding part way 
through the tooth . 

This paper compares the results of aging deer based on wear- 
class, incisor-sectioning and on incisor -grinding methods to evaluate the relative 
merits of the latter two in terms of the effort required for results obtained. 

MATERIALS AND METHODS 

A collection of jaws was made from deer shot on the Bruce 
Peninsula, Ontario during the open seasons of 1966 and 1967. 

The estimate of age for each jaw was made by several qualified 
personnel on the basis of wear-class. These jaws were then tagged numerically 
before the incisors were extracted. 

The method of extracting the first incisors followed that of 
Bergerud and Russel (1966). A great deal of care is necessary when the teeth are 
being extracted so that they are not cracked or broken. The fresher jaws are 
when the extraction is carried out, the less chance there is of damaging the 
teeth. The incisors were then placed in small envelopes and numbered corres- 
ponding to the jaw number. 

The jaws obtained in 1966 were aged comparatively using the tooth- 
erosion method (Severinghaus 1949) and the incisor-sectioning method of Gilbert 
(1966). After the incisors had been decalcified, sections were cut at 6 to 9 
microns. A decalcification time of 100 hours rather than 96 as suggested by 
Gilbert (1966) provided better sections. The remainder of the procedure was 
consistent with that of Gilbert (1966) . 

The estimate of age for each jaw was made by several qualified 
agers . This age was considered the true age of the animal. These jaws were 
then tagged numerically before the incisors were extracted. The age determina- 
tion based on cemental annuli was compared with the wear-class. 

The incisors removed from jaws collected in 1967 were ground by 
pushing the side of the tooth against a 5-inch diameter, medium-grade carborun- 
dum stone. The root portion was ground longitudinally to approximately mid-way 
through the tooth. Both the anterior and posterior sections of the tooth were 
exposed. The exposed surface was then polished on #400-grit, wet and dry emery 
paper. The polished surface was moistened with a drop of glycerine and the 
tooth examined using a binocular microscope with 100X power. Reflected light 
was provided by a focusing objective with variable rheostat. Best results were 
obtained by using the brightest light possible. 

The most consistent readings of annuli were obtained by examining 
the bottom third posterior portion of the tooth. Comparative readings from the 
posterior and anterior portions of the tooth indicated that the number of annuli 
on the posterior portion was higher than the number of annuli on the anterior 
portion. 



10 



The cemental area of the tooth is bounded on the interior by 
white dentine and on the exterior by the white enamel. Between these two are the 
alternate white and grey bands that constitute the annuli. The age of animals 
was obtained by counting the number of bands and adding %-year. Some judgement 
is required in making age determinations because of the presence of incomplete 
lines that resemble annuli. Where possible the milk and permanent incisors of 
fawns were aged. 

RESULTS AND DISCUSSION 

A total of 312 jaws were collected from the Bruce Peninsula for 
this study. However, comparative ages were made on only 53 jaws for the tooth- 
erosion and incisor-sectioning methods and on only 192 jaws for the tooth- 
erosion and incisor-grinding methods. 

A summary of the two comparisons is presented in Table I. The 
variability within and between the comparisons is difficult to explain. Imme- 
diately the methodologies become suspect. However, all age determinations were 
checked more than once by the authors as well as others proficient in the 
techniques. We do feel that the quality of the reflected light used could have 
been improved. 

Erosion Versus Incisor-Sectioning : Although the trend is not 
continuous through all ages, the percent error between erosion and incisor- 
sectioning increases with age. No difference was observed between the two 
methods in determining the ages of %-, 4%-, and 5%-year-olds . The errors ranged 
from 0.0 percent for %-year-olds to 75 percent for 8%-year-olds . 

The computation of mean age based on the two techniques was 2.91 
years for the tooth-erosion method and 3.33 years for the incisor-sectioning 
method. The high average age based on incisor-sectioning reflects the greater 
numbers of higher age. Only one sample was aged 8%-years-old on the basis of 
tooth-erosion but 4 were classed in this age group by the incisor-sectioning 
method. 

The effort required to age 100 samples by the tooth-erosion 
method was calculated to be 2 man-hours while the incisor-sectioning method 
required 65 man-hours . 

Erosion Versus Incisor-Grinding : The same loose trend of 
increasing per cent error with age of the jaw is evident in the comparison of 
tooth-erosion versus incisor-grinding techniques. The most notable disparity 
existed in the fawn class where one fawn (tooth-erosion) was considered a 
yearling based on a count of cemental annuli. Differences were also noted in 
the yearling group. 

The average ages of samples in each method of age determination 
were more closely aligned than were the previous methods; 2.30 years based on 
tooth-erosion compared to 2.53 years based on cemental annuli. A comparison of 
the ages determined by each of these methods is summarized in a different manner 
in Table II. Here, individual samples are identified by age for each method. 
In this type of analysis, the expected pattern is for the data to group around 
the comparative age both vertically and horizontally. This actually holds only 
for the \- and 1%-year-old age classes. 

11 



TABLE I 



A COMPARISON OF THE AGES DETERMINED BY THE 

EROSION PATTERN WITH THE AGES DETERMINED BY A COUNT OF 

CEMENTAL ANNULI IN THE FIRST INCISORS OF WHITE -TAILED DEER 



NUMBERS IN EACH AGE- 
CLASS DETERMINED BY 
AGE -CLASS TOOTH INCISOR- 
(YEARS) EROSION SECTION 



PER CENT 
ERROR 



NUMBERS IN EACH AGE- 
CLASS DETERMINED BY 
TOOTH INCISOR- 
EROSION GRINDING 



PER CENT 
ERROR 



0-1 


9 


9 


0.00 


53 


52 


1.88 


1-2 


13 


12 


7.69 


50 


41 


18.00 


2-3 


11 


8 


27.27 


29 


41 


41.37 


3-4 


4 


5 


25.00 


20 


17 


15.00 


4-5 


5 


5 


0.00 


21 


19 


14.28 


5-6 


7 


7 


0.00 


11 


12 


9.09 


6-7 


3 


1 


66.67 


7 


4 


42.85 


7-8 


- 


2 


- 


1 


3 


66.66 


8-9 


1 


4 


75.00 


- 


- 


- 


9-10 


- 


- 


- 


- 


- 


- 


10-11 


- 


- 


- 


- 


- 


- 


11-12 


- 


- 


- 


- 


1 


- 


12-13 


- 


- 


- 


- 


1 


- 


13-14 


- 


- 


- 


- 


1 


- 


TOTAL 


53 


53 




192 


192 




MEAN AGE 


2.91 


3.33 




2.30 


2.53 





12 



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o 


o 


H 


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The aberrant age determination of a yearling (wear-class) as 
a fawn is difficult to explain. Could an early fawn dropped in March develop 
a premature yearling tooth condition by its first fall? 

Similarly in the yearling wear-class, one jaw was aged as a 
fawn based on cemental annuli. Could a short yearling still retain its milk 
teeth? 

In answer to these two rhetorical questions, we can only point 
out that aberrant tooth development and wear must be expected in light of known 
anomalies in human dentition. 

As one progresses through the early adult to full adult ages 
(wear-class), the range of ages based on cemental annuli increases to the extent 
that we suspect the value of wear-class as a valid technique to determine specific 
year-class. However, we feel that the technique is justified in establishing 
three age-groups; fawns, yearlings and adults. Since we have yet to see any 
valid use of year-class data collected in the past, and since the wear-class 
method cannot provide accuracy, we suggest that if the wear-class method is to 
be used, only age-groupings be attempted. 

The effort to prepare 100 samples for incisor-grinding was com- 
puted to be 14 man-hours . 



REFERENCES 



Bergerud, A. T. and H. L. Russel, 1966. Extraction of incisors of Newfoundland 
caribou. Journal of Wildlife Management 30: 842-843. 

Gilbert, F. F., 1966. Aging white-tailed deer by annuli in the cementum of the 
first incisor. Journal of Wildlife Management 30: 200-202. 

Mansell, W. D., 1967. Fecundity, fertility and natality of white-tailed deer 

in the Bruce Peninsula, Ontario. Unpublished Master of Science 
Thesis, University of Guelph. 77 pp. 

Ransom, A. B., 1966. Determining age of white-tailed deer from layers in cem- 
entum of molars. Journal of Wildlife Management 30: 197-199. 

Sergeant, D. E. and D. H. Pimlott, 1959. Age determination in moose from 

sectioned incisor teeth. Journal of Wildlife Management 23: 
315-321. 

Severinghaus, C. W., 1949. Tooth development and wear as criteria of the 

in white-tailed deer. Journal of Wildlife Management 13: 195- 
216. 

Simkin, D. W., 1967. Comparison of three methods used to age moose. Proc . N. E. 
Section Wildlife Soc, Quebec, P. Q., Feb. 12-15. 



14 



AN ALTERNATE METHOD OF ASSESSING 
SNOW QUALITY 



by 



S. A. MUNROE, Deer Range Biologist 
Parry Sound District 



ABSTRACT 



During the winter, 1969-70, Parry Sound 
District staff tested a device, designed in 
Michigan, to gather information on snow com- 
paction as it relates to deer. This device 
has a number of inherent flaws, but with more 
consistent timing and technique, the device 
could be an effective tool in assessing snow 
support qualities. 

INTRODUCTION 

In an attempt to establish a more valid method of assessing 
snow-support quality in winter deer range, Parry Sound District tested a device, 
designed in Michigan by Verme (1968), at its eight snow stations during the 
winter of 1969-70. 

Criticism has been periodically raised concerning our present 
system of recording snow data. Snow depth records are satisfactory, but the 
method of assigning "A," "B" or "C" (Passmore 1953) to crust strengths has faults. 
One such problem commonly arises in the assignment of crust strength as "C." The 
Passmore snow rating system assigns severity-index points to such conditions, 
which are intended to indicate a hindrance to deer, when in fact these heavy crusts 
are to their advantage. Another inherent problem in the system is that crust 
strength evaluations are subject to errors or inconsistancies in human judgement. 

METHODS 

The device, described by Verme (1968) as a "compaction gauge" 
consists of a 2-foot length of one inch (diameter) copper tubing, filled with 
enough to make it weigh three pounds. These gauges were constructed at a cost 
of $3.00 (for materials) per unit. 

The field technique simply involved lowering the device, by an 
attached cord, until the base just touches the snow, then releasing it. The 
depth the gauge penetrated the snow represented the support factor of snow 

15 



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(snow compaction) subjected to a vertical force of 3 lb. per sq. inch. According 
to Verme (1968) these depths represented numerical values for total resistances 
offered to deer by the composition of snow. 

Thus in addition to the regular snow depth readings, a measure- 
ment was made of snow compaction at each snow station. Notes were made of the 
temperature at the time of survey and of the low temperature of the previous 
night. The system of making snow readings on Monday morning of each week was 
adhered to. Several of the officers were encouraged to make readings during the 
morning and again in the afternoon to see how snow-packing conditions might change 
as the day progresses. 

At Arrowhead Provincial Park and Still River, daily records were 
made of maximum and minimum temperatures from mid-December through the end of 
March . 



RESULTS AND DISCUSSION 

The results of all 1969-70 snow records from the eight snow sta- 
tions in the District are summarized in Table I, and illustrated in Graph I. 

As Table I and Graph I indicate, the uncrusted to lightly 
crusted snow which prevailed through most of the past winter failed to prevent 
the compaction gauge from "going right through." Gauge depths almost equalled 
snow depths; snow compaction was next to nil. Temperatures were extremely cold 
(Table II), and the snow remained virtually uncrusted until early February. 
Only light crusts were formed at this time due to the absence of prolonged 
periods of thaw. Crusts capable of supporting deer were not formed until late 
March-early April. Data accrued from the snow stations indicated a severe 
winter, for the mean index points (Passmore 1953) per station was 22.3. 



TABLE II 



SUMMARY OF TEMPERATURE RECORDS 





FROM ARROWHEAD PROVINCIAL 


, PARK AND STILL 


RIVER 








PARRY SOUNI 


) DISTRICT, 1969-70 










ARROWHEAD 


PARK 






STILL 


RIVER 




MEAN 


MEAN 






MEAN 


MEAN 




MONTH 


MAX. 


MIN. 


EXTREMES 


MAX. 


MIN. 


EXTREMES 


December, 1969 


17.6 


-3.2 


(+28) 


(-23) 


21.0 


-10.0 


(+36) (-38) 


(18-31) 
















January, 1970 


14.4 


-5.9 


(+37) 


(-32) 


21.0 


-12.7 


(+40) (-42) 


February, 1970 


20.1 


0.8 


(+40) 


(-26) 


23.0 


- 2.7 


(+44) (-44) 


March, 1970 


31.6 


9.3 


(+48) 
18 


(-12) 


31.1 


5.5 


(+55) (-24) 



Not until after the formation of heavy crusts in March did 
differences occur between the Passmore (1953) system and the compaction gauge 
method of the interpretion of snow severity as related to deer (Fig. 1) 
(Table I) . Mean morning compaction gauge readings for March 9, 16 and 23 were 
13.5 inches, 14.4 inches and 19.9 inches respectively. For these same dates, 
mean snow severity index points for eight snow stations were 2.63, 2.38 and 1.38 
respectively. According to the Passmore (1953) system, these ratings (mean index 
points) would suggest that snow conditions were severe for March 9 and 16, and 
moderate for March 23. The data from the compaction gauge method suggests an 
opposite view. The question is--which interpretion is true with regards to deer. 

This snow compaction method of assessing snow conditions does 
have a number of shortcomings . 

(1) Light melt crusts often prevent gauge penetration when 
measuring is done early in the morning. From this, one could assume that the 
crust would support deer, but this assumption would be false. This fault could 
be corrected if snow compaction readings are made in the early afternoon, when 
light crusts have disappeared. These mid-day measurements however, are believed 
not to be representative of snow conditions which prevail through three-quarters 
of the 24 hour day. An indication of how snow crust (and compaction) change 
through the day is found in Table III. 

(2) The vertical force of 3 lb. per sq. inch for this device is 
probably not a true indication of the downward force of a walking deer. 

(3) The device gains momentum as it penetrates the top snow 
layer. Such a factor has resulted in some compaction gauge readings being 
greater than snow depth readings, especially early in the winter. The device 
was penetrating one to two inches into the litter layer. 



TABLE III 



TIME RELATED FLUCTUATIONS IN 
COMPACTION GAUGE PENETRATION AT PAKESLEY SNOW STATION, 1970 



DATE 



MORNING COMPACTION 
GAUGE READING (IN.) 



AFTERNOON COMPACTION 
GAUGE READING (IN.) 



March 9, 1970 

March 16, 1970 

March 23, 1970 

April 6, 1970 



1.2 

8.3 

16.8 

0.0 



12.0 
10.1 

25.7 
11.4 



19 



CONCLUSIONS 

The snow compaction device, herein described, is subject to a 
number of inherent flaws, but could be an effective tool in assessing snow 
support conditions, providing timing and technique are consistent. A better 
tool for assessing such conditions requires a downward pressure similar to that 
of a walking deer. Hepburn (personal communication) has designed such an apparatus 
which appears to be the answer to our problem. We hope his device will be 
available for the coming winter period. If not, we recommend testing this snow 
compaction gauge in our District during the 1970-71 winter. 



REFERENCES 

Passmore, R. C, 1953. Snow conditions in relation to big game in Ontario 

during the winter of 1952-53. Ontario Dept . of Lands & Forests, 
Wildl. Res. Rep. 2. 12 pp . 

Verme, L. J., 1968. An index of winter weather severity for northern deer. 
Jour. Wildl. Mgmt. 32 (3): 566-574. 



20 



INTRODUCTION 



A STUDY OF MOOSE BROWSING AND POPULATION DECLINE 
ON TWO ISLANDS OF LAKE NIPIGON 



by 



B. H. GIBSON, Biologist 
Geraldton District 



ABSTRACT 



The results of a 1969 browse and pellet group 
survey are compared with the results of a 1964 
study on the same two sites. The decline in moose 
on the two islands does not seem to be due to 
natural factors (e.g. overbrowsing) . Balsam fir 
increased in quantity since 1964 on both islands. 
It comprises 85. 6% of all live browse stems on 
Shakespeare Island and 56.8% on Kelvin Island. 
There is a greater number of live browse stems on 
the Shakespeare Island study area than in 1964; no 
increase occurred on Kelvin Island in the interval. 
There is a general decline in the percentage of 
stems browsed for most species on both study areas. 
This indicates a population decline. Balsam fir 
will increase in abundance on both islands as a 
result of forest succession. Balsam fir appears 
to be suitable for moose browse, even when it 
forms the bulk of their diet. Nutritional studies 
of fir are required to determine this. Pellet 
group studies and aerial surveys confirm the decline 
of moose between 1964 and 1969. Management of the 
Lake Nipigon moose herd is recommended. This would 
involve experimental habitat manipulation, ecolo- 
gical studies and a regulated harvest. 



The islands of Lake Nipigon have been established as a moose 



management unit . 

The 1969 browse and pellet group study was conducted to compare 
results with the 1964 study. Prior to 1965, the Lake Nipigon Islands were with- 
in a Crown Game Preserve. Aerial counts of moose during the winter of 1964-65 
revealed 71 moose on Shakespeare Island and 33 on Kelvin Island (Table I) . This 
resulted in a density of 3.3 moose per square mile for Shakespeare Island and 
1.2 per square mile for Kelvin Island (Gibson, 1964). 



21 



TABLE I 



AERIAL COUNTS OF MOOSE 
ON LAKE NIPIGON ISLANDS BETWEEN 1964 AND 1970 



LOCATION 



1970 1969 1968 1967 1966 1965 1964 



Shakespeare Island 12 

Kelvin, Wilson, 
Endakwis, Islands 
(combined totals) 21 



18 



31 



23 



39 



20 



60 



36 



32 



71 



43* 



TOTALS 



33 



49 



62 



80 



68 114 



Note: In 1964, 33 of the total of 43 moose were seen on Kelvin Island. 



Because of the high densities of moose recorded, range dmaage was 
suspected. The surveys were conducted to determine if this was true. The 1964 
study indicated that browse species had experienced heavy browsing. Pellet group 
counts suggested a density of 6.5 to 13.4 moose per square mile on Shakespeare 
Island and 5.1 to 11.6 on Kelvin Island (Table II). 



TABLE II 



NUMBERS OF PELLET GROUPS OBSERVED AND 



MOOSE DENSITIES INDICATED 



LOCATION 



NO. OF GROUPS MOOSE DENSITY INDICATED 
1969 1964 1969 1964 



% CHANGE INDICATED 



Shakespeare Island 2 
Kelvin Island 28 



56 
48 



0.36 
4.96 



9.96 
8.39 



- 2777% 
59% 



Since opening the Islands to hunting in 1965, there has been an 
almost continuous decline in moose on Shakespeare and Kelvin Islands (Table I) . 
Potential reasons for these declines were: 

(1) A large scale egress of moose from the islands. 

(2) Natural mortality increased due to diseases, parasites, 
reproductive decline, etc. 

(3) A range quality decline (e.g. over-browsing). 

(4) The effects of hunting (e.g. overharvest) . 



22 



There is no evidence that an emigration of moose has occurred. 
Some movement from the Islands probably occurs, but there is likely a "two-way" 
movement, with moose also moving from the mainland to the Islands. Theoreti- 
cally, ingress and egress should be approximately equal. The "net" number of 
moose remaining should be roughly the same. 

In March of 1965, a total of three moose were shot from 
Shakespeare Island and the closely associated Macoun Islands. This was done to 
determine the physical condition of the herd and to discover the effects of an 
almost pure balsam diet on moose. The two bulls and one cow collected were 
weighed, all internal organs were collected and winter tick specimens were 
taken from the hides; ticks appeared to be present in relatively low numbers. 
Dr. Fyvie of the Research Branch studied the internal organs. She found that the 
three moose actually had a lower infestation rate of common parasites than many 
mainland sub -populat ions . All of the animals appeared to be in good condition 
and had fat reserves in the abdominal cavity. The female carried a well 
developed and apparently normal foetus. 

Wolves were present in 1964 around the Islands. Even so, the 
moose population was able to reach 71 animals. Wolves do not appear to have 
increased since 1964. There is no evidence to indicate that they have been re- 
sponsible for the decline in moose. 

Over-browsing and a range quality decline are obvious area to 
study in determining the causes of the present decline in moose. The results of 
the 1969 browse study indicate however, that there is more browse and less browsing 
than in 1964 on Shakespeare Island. This will be discussed in greater detail in 
this report. 

I believe that the decline in moose observed in the annual aerial 
surveys is due primarily to heavy hunting pressure. The population, especially 
on Shakespeare Island, has yielded a high harvest, particularly during 1965-1967 
inclusive (Table III) . The estimated annual legal kill has declined as has the 
total number seen in the annual aerial surveys for most years. 

TABLE III 



REPORTED MOOSE KILL FROM 



LAKE NIPIGON ISLANDS AND SHORELINE OF MAINLAND 



1969 1968 1967-68 1966-67 1965-66 



Number of moose 26 57 67 75 75-100 



23 



After completing the 1969 aerial survey and counting a total of 
9 moose on the two Islands, we recommended a complete closure of all Islands to 
moose hunting in 1969. A closure was not achieved in 1969 but was in 1970. We 
can now monitor population changes (e.g. increases) without the biasing effects 
of hunting. 

In summary, each of the potential welfare and decimating factors 
had to be studied to determine which one(s) caused the decline in the moose herd. 
A study of each was necessary to determine in which direction our moose manage- 
ment program should be headed. 

DESCRIPTIONS OF STUDY AREAS 

Kelvin Island is the largest of the islands of Lake Nipigon, 
with an area of 26.4 square miles. The area of Shakespeare Island is 21.6 
square miles. The two islands comprise approximately 16 per cent of the total 
area of the Lake Nipigon Islands. 

Shakespeare Island is separated from the nearest mainland by 
four miles of open water. Kelvin Island is six miles from the closest mainland. 
However, there is movement of moose between Shakespeare Island and the small 
adjacent Macoun Islands to the south-east. There is inter-island movement of the 
moose populations between Kelvin and Wilson and Endakwis Islands. 

The two islands are typically Archean. They are extremely 
rugged and hilly in some areas, particularly on Kelvin Island. At the south east 
end of this island the bluffs rise steeply to nearly 400 feet above Lake Nipigon. 
Well-drained uplands with swamps in the lowlands are common. The region's relief 
class is one of moderately to strongly broken areas with moderate to steep slopes. 
The soil is primarily a silty sand, the result of an outwash plain. For the most 
part, the soil is well drained but is generally moist due to thick mats of 
Lycopodium and Hylocomium which cover large areas of both islands. Soil depth 
is not known, but is probably not deep. It is apparently a moderately fertile 
soil . 

On Shakespeare and Kelvin Islands, approximately 2 per cent of 
the area is water; one per cent is nonproductive forest land and 97 per cent is 
estimated to be productive forest land. There are no dense mature conifer stands 
now on the two islands. Spruce budworm attacks about 1943 eliminated most of the 
mature balsam fir. Medium to heavy windthrows of conifers and deterioration of 
hardwoods followed. Accelerated growth of balsam fir seedlings and saplings 
occurred due to release. 

The mixed woods have lost a large portion of their mature conifer 
content since 1947. Because of overmaturity, the hardwood components are break- 
ing up rapidly. Dense second growth balsam fir up to 25 feet in height, and one 
to 30 years old, form approximately 75 per cent of the total productive forest 
areas of the two islands compared with an estimated 66% in 1964. Natural 
conversion of the stands to young conifers is imminent. Excellent regeneration 
of white spruce and black spruce is occurring on Shakespeare Island. Scattered 
mature and overmature black and white spruce, white birch and trembling aspen are 
still found but are of little numerical importance. Many of the remaining white 
spruce are exceptionally tall and robust specimens, suggesting the two islands are 
ideal sites for white spruce. 

24 



On the browse survey sites, second growth balsam fir is extremely 
dense. With the regenerating white spruce, the balsam fir will soon provide the 
climax forest. The dense balsam fir canopy, combined with heavy browsing by 
moose, is limiting regeneration of shrub species to small, open areas among the 
fir or to sucker growth where the original stems were killed by browsing or 
intolerance to shade. The scattered deciduous browse species are comprised 
mainly of mountain maple, white birch and mountain ash. Kelvin Island appears 
to be from 5 to 10 years behind Shakespeare Island in forest succession. 

No major disturbances have been reported since the spruce bud - 
worm outbreak between 1943 and 1949 that deciminated most of the mature balsam 
on both Shakespeare and Kelvin Islands. No large fires have occurred on either 
island. Some minor cutting operations were conducted on the west and east shore 
of Shakespeare Island between 1940 and 1950. Mature and overmature white and 
blakc spruce were taken. During the same period, limited saw-log operations were 
conducted on the northwest shore of Kelvin Island, but these were of a very 
limited nature. Neither of the two browse survey sites was in the previously 
logged areas . 



BROWSE SURVEY METHOD 

The same one square mile sites, first sampled in 1964, were 
chosen. The transects were run as close to the 1964 lines as possible. Exact 
replication of the previous survey was impossible because the original transects 
were not permanently marked. The two survey sites are representative probably 
of the two islands. 

Shakespeare Island was surveyed on May 21 and 22 and Kelvin 
Island on May 23. Late May was the best time for the surveys because vegetation 
is just starting to develop at this time. Positive identification of browse 
species is facilitated as a result. 

The survey method consists of sampling an area to obtain the 
percentage occurrence of available winter browse and the degree of utilization 
by moose. 

Maps of a two-inch to the mile scale were used. With the aid 
of aerial photographs we preselected the survey areas to avoid swamps, streams 
and lakes that we could not cross. This factor might have biased our results to 
some degree. Four parallel lines, each spaced 16 chains apart, were marked on 
the field maps to cross the topography at right angles to get a more representa- 
tive sample of the terrain and plant species. On both islands, this meant a 
compass bearing of northwest or southeast had to be followed. 

We located our sample areas near shore. This made access easier. 
Finding the areas for subsequent browse studies would also be easier by situating 
the plots near the shores of the islands. In addition, we would have an area 
where browse conditions would be known and where follow-up management programs 
would be facilitated by the study areas? proximity to the shore. 

The browse survey method was a modified version of the Passmore, 
Hepburn (1955) method of range appraisal. The revised method was outlined in a 
1963 memorandum by Wildlife Biologist J. B. Dawson of Maple. 



25 



The sampling rate was 64 plots for each of the one square mile 
areas. Sixteen plots were located on each of the four parallel transects which 
were one mile long. Individual plot size was 66 feet by 2 feet or 1/330 of an 
acre. The lines were chained using a two chain tape. Between each plot, a four 
chain spacing was used. In other words, every four chains marked the start of a 
plot. 

Compass bearings were maintained with a Sylva compass. The two- 
man crew was comprised of P. Drysdale and R. Sheenan who were third and second 
year biology students respectively. They were loaned to the District for the 
study by the Thunder Bay District where they had been trained in browse identi- 
fication. They later conducted extensive browse studies in the Thunder Bay and 
White River Districts. 

Observations were recorded of moose browsing on the ten most 
commonly browsed species. Table I lists these along with browsing information. 
These observations were made one foot on each side of the chain. Only browse 
plants with the stem within one foot of the chain were recorded. Browse species 
under two feet in height were not recorded because they would be covered with 
snow in the winter and not browsed by moose. Stems over ten feet high were also 
not recorded, because these are too high for moose to browse. 

Plot records--Under L : The number of living plants of each of 
the ten species or genera was included. The maples, poplars, willows and dogwoods 
were grouped by genus rather than species. This column refers to live stems 
available for moose feed between two and twelve feet high. 

Under K : The number of stems of the ten species (genera) killed 
by previous moose browsing. We did not include plant mortality caused by hares 
or mice in this category. 

Under B : The number of stems in each of the ten species or 
genera which were browsed from the previous fall to the time of the browse survey. 

Under H : The number of plants in each species or genera showing 
moderate to heavy browsing. The plant may be deformed, may produce more browse 
for a time through branching, or it may eventually be weakened or killed. 

Note : If a stem were browsed or hedged, and alive, it was 
recorded in each of these categories on the tally forms. "E" refers to totals 
i.e. EB = Total stems browsed. 



RESULTS 

The data collected in the field were compiled in the following 
way for each of the ten species or genera and for each island separately. 

(1) Frequency index - -which is a measure of distribution over 
the area sampled and calculated as: 

Number of plots on which each species occurs divided by 
the number of plots in the sample. 

(2) Living stems of each species per acre --which is a measure 
of productivity calculated as: 

26 



EL x 330 divided by the number of plots in the sample. 

(3) Percentage of plants browsed --a measure of current use for 
each of the species, calculated as: 

E B 

E L (for each species) 

(4) Percentage of plants killed from browsing --a measure of 
past use for each of the ten species, calculated as: 

E K x 100 
E K + E L 

(5) Percentage of stems in each species which show hedging 
effect --an additional measure of past use, calculated as: 

EH x 100 

E L 

(6) Percentages of available browse supplied by all ten species 
which is supplied by each of the species --a measure of relative availability, 
calculated as: 

E L (single species) x 100 
E L (all species) 

OBSERVATIONS AND DISCUSSION 

1. Frequency Index 

Balsam fir was the most widely distributed browse species during 
the 1969 survey with a frequency index of 0.89 on Shakespeare Island (Table IV) . 
This is down slightly from 0.92 in the 1964 survey, but this is not a signifi- 
cant reduction. On Kelvin Island, balsam fir was more widely distributed on the 
plots than in 1964 with a frequency index of 0.92 in 1969 and 0.81 in 1964. This 
indicates that balsam fir is becoming more widely distributed on Kelvin Island. 

An increase in the frequency index occurred for white birch on 
Sahkespeare Island. In 1964, for example, white birch occurred on only 7 plots; 
in 1969 it occurred on 16 plots. The frequency index for white birch increased 
slightly in the 1969 study on Kelvin Island. 

Some species that were rare or absent during the 1964 study are 
increasing. Mountain ash was found on more plots on Shakespeare Island during 
the 1969 study. On Kelvin Island, it appeared to decline greatly in frequency, 
occurring on 38 plots in 1964 and only 14 in 1969. Willows were recorded on only 
one plot on Shakespeare Island in 1969 and on none in 1964. Conversely, on 
Kelvin Island willows declined, being found on 4 plots in 1964 and only one in 
1969. Maples were less widely distributed on Shakespeare Island in 1969, 
occurring on only two plots. Maple distribution also declined on Kelvin Island, 
occurring on eight plots in 1969 compared with 44 in 1964. 



27 



TABLE IV 



COMPARISON OF OCCURRENCE AND UTILIZATION 
OF BROWSE SPECIES FOR THE 1964 AND 1969 SURVEYS 



KELVIN ISLAND 























FREQUENCY 


CALCULATED LIVING 










BROWSE SPECIES 


INDEX 


STEMS 
1969 


PER ACRE 
1964 


PER CENT 
1969 


BROWSE! 
196 


) 




1969 


1964 


•4 


White Birch 


0.73 


0.67 


1026.1 


752.8 


32.2 


(199) 


92.5 


(146) 


Balsam Fir 


0.92 


0.81 


1670.6 


1000.3 


54.6 


(324) 


49.5 


(194) 


Mountain Ash 


0.22 


0.59 


82.5 


340.3 


12.5 


(16) 


96.9 


(66) 


Willows 


0.02 


0.06 


5.16 


41.2 


100.0 


(1) 


87.5 


(8) 


Maples 


0.12 


0.69 


67.0 


959.1 


61.5 


(13) 


89.2 


(186) 


Dogwoods 


0.00 


0.20 


0.0 


170.2 


0.0 




100.0 


(33) 


Cherries 


0.00 


0.00 


0.0 


0.0 


0.0 




0.0 




June Berries 


0.05 


0.05 


61.9 


25.8 


25.0 


(12) 


20.0 


(5) 


Poplars 


0.05 


0.12 


25.8 


56.7 


60.0 


(5) 


90.9 


(11) 


Hazel 


0.00 


0.00 


0.0 


0.0 


0.0 




0.0 




Black Spruce 


0.25 


— 


103.1 


— 


0.0 




-- 




Cedar 


0.48 


-- 


154.7 


— 


16.7 


(30) 


— 




Alder 


0.28 


— 


92.8 


— 


0.0 




-- 




Honeysuckle 


0.00 


— 


0.0 


— 


0.0 




-- 





TOTALS 



3336.1 



3346.4 















PER CENT 


SUPPLIED 


PER CENT 


BROWSE SPECIES 


PER CENT 


KILLED 


PER CENT 


HEDGED 


BY EACH 


SPECIES 


CHANGE 




1969 




1964 


1969 


1964 


1969 


1964 




White Birch 


14.2 




5.8 


13.1 


28.8 


34.9 


22.5 


+12.4 


Balsam Fir 


1.5 




0.0 


1.5 


14.9 


56.8 


29.9 


+26.9 


Mountain Ash 


77.8 


(56) 


87.5 


77.3 


2.8 


10.2 


- 7.4 


Willows 


0.0 




11.1 


0.0 


0.0 


0.2 


1.2 


- 1.0 


Maples 


76.4 




26.5 


30.8 


27.4 


2.3 


28.7 


-26.4 


Dogwoods 


0.00 




26.7 


0.0 


51.5 


0.0 


5.1 


- 5.1 


Cherries 


0.0 




0.0 


0.0 


0.0 


0.0 


0.0 


0.0 


June Berries 


29.4 




0.0 


0.0 


0.0 


2.1 


0.8 


+ 1.3 


Poplars 


64.3 




50.0 


0.0 


36.4 


0.9 


1.7 


- 0.8 


Hazel 


0.0 




0.0 


0.0 


0.0 


0.0 


0.0 


0.0 


Black Spruce 


0.0 




— 


0.0 


— 


— 


— 




Cedar 


0.0 




— 


0.0 


— 


— 


— 




Alder 


0.0 




— 


0.0 


-- 


— 


-- 




Honeysuckle 


0.0 




— 


0.0 


— 


-- 


— 





28 



TABLE IV (CONTINUED) 

COMPARISON OF OCCURRENCE AND UTILIZATION 
OF BROWSE SPECIES FOR THE 1964 AND 1969 SURVEYS 
SHAKESPEARE ISLAND 



BROWSE SPECIES 



FREQUENCY 
INDEX 



CALCULATED LIVING 
STEMS PER ACRE 



PER CENT BROWSED 





1969 


1964 


1969 


1964 


1969 


1964 


White Birch 


0.25 


0.10 


139.2 


51.6 


44.4 


(27) 


100.0 


(10) 


Balsam Fir 


0.89 


0.92 


2210.8 


1876.9 


43.4 


(452) 


80.5 


(364) 


Mountain Ash 


0.19 


0.03 


144.4 


10.3 


28.6 


(8) 


100.0 


(2) 


Willows 


0.02 


0.00 


10.3 


0.0 


0.0 


(2) 


0.0 




Maples 


0.31 


0.12 


10.3 


72.2 


100.0 


(2) 


78.6 


(14) 


Dogwoods 


0.00 


0.00 


0.0 


0.0 


0.0 




0.0 




Cherries 


0.00 


0.00 


0.00 


0.0 


0.0 




0.0 




June Berries 


0.12 


0.02 


72.2 


5.2 


57.1 


(14) 


0.0 


(1) 


Poplars 


0.47 


0.02 


15.5 


5.2 


0.0 


(3) 


100.0 


(1) 


Hazel 


0.00 


0.00 


0.0 


0.0 


0.0 




0.0 




Black Spruce 


0.39 


— 


273.3 


— 


0.0 




-- 




Cedar 


0.36 


— 


531.1 


— 


15.5 


(103) 


-- 




Alder 


0.78 


— 


159.8 


— 


3.3 




— 




Honeysuckle 


0.16 


— 


5.2 


— 


100.0 


(1) 


— 





TOTALS 



2602.7 



2021.4 













PER CENT 


SUPPLIED 


PER CENT 


BROWSE SPECIES 


PER CENT 


KILLED 


PER CENT 


HEDGED 


BY EACH 


SPECIES 


CHANGE 




1969 


1964 


1969 


1964 


1969 


1964 




White Birch 


43.7 


61.5 


14.8 


70.0 


5.1 


2.5 


+2.6 


Balsam Fir 


0.4 


0.3 


0.4 


46.9 


85.6 


92.9 


-7.3 


Mountain Ash 


26.3 


33.3 


42.9 


100.0 


5.3 


0.5 


+4.8 


Willows 


0.0 


0.0 


0.0 


0.0 


0.4 


0.0 


+0.4 


Maples 


0.0 


57.6 


0.0 


21.4 


0.4 


3.6 


-3.2 


Dogwoods 


0.0 


0.0 


0.0 


0.0 


0.0 


0.0 


0.0 


Cherries 


0.0 


0.0 


0.0 


0.0 


0.0 


0.0 


0.0 


June Berries 


0.0 


0.0 


0.0 


0.0 


2.7 


0.2 


+2.5 


Poplars 


0.0 


0.0 


66.7 


0.0 


0.6 


0.2 


+0.4 


Hazel 


0.0 


0.0 


0.0 


0.0 


0.0 


0.0 




Black Spruce 


0.0 


— 


0.0 


-- 


-- 


-- 




Cedar 


0.0 


— 


0.0 


-- 


-- 


-- 




Alder 


0.0 


— 


0.0 


-- 


-- 


-- 




Honeysuckle 


50.0 


— 


0.0 


-- 


-- 


-- 





29 



Dogwood was absent from the plots in both 1964 and 1969 on 
Shakespeare Island. Dogwood declined on Kelvin Island in the interval; it was 
found on 13 plots in 1964 and on none in 1969. Cherries were not found during 
1964 or 1969 on any plots on either island. Juneberries were more widely 
distributed on Shakespeare Island in 1969, occurring on 8 plots compared with one 
in the previous survey. On Kelvin Island, no change occurred, with Juneberries 
occurring on three plots on both surveys. Poplars were found on only one plot 
on Shakespeare Island in 1964, and on three plots in 1969. Three plots on 
Kelvin Island supported poplars in the 1969 survey, compared with 8 plots in the 
previous survey . 

As in the 1964 survey, the frequency index for most of the ten 
browse species was higher on Kelvin Island. This indicates a wider distribution 
of most of the species there. The low frequency index for many of the browse 
species, especially on Shakespeare Island is probably due to a combination of 
forest succession and past intensive browsing by moose. The dense balsam canopy 
on Shakespeare Island probably prevented regeneration of shrubs. Any shrubs 
reaching browseable height were usually heavily browsed and hedged and often 
died as a result. The higher frequency index of shrubs on Shakespeare Island 
in 1969 is due probably to reduced browsing intensity. This, in turn, is probably 
due to the decline in the moose population since 1965. 

On Kelvin Island, shrubs are more widely distributed, because of 
less crown closure and a lower moose population than on Shakespeare Island. 

2 . Living Stems of each Species per Acre 

White birch, balsam fir and mountain ash have increased since 
1964 on Shakespeare Island. Balsam fir showed a 17.8% increase in live stems 
per acre (Table IV). An increase in balsam of 67.1% occurred on the Kelvin 
Island study area. Balsam comprised 85.6% of all live browse stems on Shakespeare 
Island and 56.8% on Kelvin Island. Birch increased on Kelvin Island since 1964, 
but mountain ash declined. Most of the other browse species on Shakespeare Island 
showed little change since 1964 in the number of living stems per acre. 

On Kelvin Island, several species appear to be declining, including 
willows, mountain ash and maples. Maples declined from a calculated 959 stems per 
acre in 1964 to 67 in 1969. Dogwood appears to have disappeared since 1964 on 
the Kelvin Island study area. Juneberries and poplars seem to have increased 
slightly on both islands since 1964. An overall increase of 28.8% in total live 
browse stems per acre is indicated for Shakespeare Island and a 0.29% decrease for 
Kelvin Island. On Kelvin Island there was almost the same total number of browse 
stems as in 1964, but the amounts supplied by each species changed. Balsam fir, 
for example, increased by approximately 60%. In the 1964 study, Kelvin Island 
supported 1325 more live browse stems per acre than the Shakespeare Island study 
area (Gibson, 1964) or about 65.5% more live stems. This declined to only 733 
more live stems per acre on Kelvin Island in 1969. 

The increases in total live stems, especially on Shakespeare 
Island are probably a result of: 

(1) The greatly reduced moose population since 1964, conse- 
quently less browsing and killing of stems would result; regeneration of stems 
would be facilitated. 

(2) There was a "good" seed year in 1964 for balsam and birch. 
These species probably increased as a result. 

30 



The reduction in some species (e.g. shrubs) on Kelvin Island is 
probably due to browsing pressure and increasing crown closure by balsam. Shrubs 
are probably being shaded out at an increasing rate. Shakespeare Island has 
largely experienced balsam succession and the subsequent decline in deciduous 
species. However, Kelvin Island appears to be 10-15 years behind Shakespeare 
Island in forest succession. 

The increases in live stems in some cases are not statistically 
valid. For example, the extrapolated totals for live stems per acre for many 
species seem significant, but the actual totals seen on the plots are not. 

3 . Per cent of Stems Browsed 

A decline in the percentage of stems browsed is evident between 
the 1964 and 1969 studies (Table IV). While 80.5% of the balsam stems were 
browsed on Shakespeare Island in 1964, only 43.4% were browsed in 1969. Birch 
were also less utilized, with 100% browsed in 1964 and 44.4% in 1969. Only two 
species (maples and Juneberries) experienced increased browsing since 1964 on 
Shakespeare Island. 

On Kelvin Island, there was an overall reduction since 1964 in 
the percentage of stems browsed, but browsing on balsam fir increased from 49.57o 
in 1964 to 54.6% in 1969. Browsing on willows increased to 100% in the 1969 study 
compared with 87.5% in 1964. 

As in 1964, there were more species and more stems of most species 
(other than balsam fir) on Kelvin Island than on Shakespeare Island. The wider 
distribution and greater abundance of the other browse species probably acts as 
a buffer, reducing the utilization of balsam fir on Kelvin Island. 

It is probable that both islands are used by moose as summer 
range. Summer food (e.g. aquatic plants) may be scarce on one or both islands. 
This has not been proved, but if there is a shortage of aquatic plants, browsing 
would likely occur during the summer also. This would increase the importance of 
browse species and might account for the high rates of browsing and hedging for 
species such as white birch and balsam. On August 5, 1965, on Shakespeare Island, 
we found that moose had browsed on the terminal leaders of balsam fir. Most of 
the fir were in the 4 to 7 foot height class. No quantitative studies were con- 
ducted. It was obvious that the browsing had occurred earlier in the summer, 
probably in mid-June. Peterson (1955) stated that conifers are practically 
untouched by moose from early spring to late fall. Because summer browsing 
occurred on Shakespeare Island, a shortage of aquatic plants may be indicated. 
Aldous and Krefting (1946) found on Isle Royale that high moose populations can 
drastically reduce growth and abundance of aquatic plants. The possibility of 
a shortage of aquatics should be investigated, especially on Shakespeare Island. 
The high moose population present in the early 1960's may have reduced water 
plants. These should, however, increase in abundance as a result of the reduced 
moose population and therefore less feeding on them. 

The study on Kelvin Island in 1969 revealed "large" areas where 
the bark had been stripped from stems of balsam fir, cedar and poplar. No 
"barking" of any stems was observed on Shakespeare Island. Murie (1939) suggested 
that the winter use of bark may indicate a food shortage. An article in the 
British Columbia Wildlife Review (December, 1967) also stated that when food 



31 



supplies are low, bark is eaten in quantity. However, Peterson (1955) believed 
that the use of bark (especially of mountain ash, poplar and cherry during May 
and early June) was preferred. Des Meules (1965:45) stated that, in Quebec, up 
to 20 pounds of bark (e.g. fire cherry) may be eaten daily; he also linked the 
barking of trees with over-browsing. He found that the most commonly barked 
species in winter was balsam fir, mountain maple and willows. Barking was 
"always encountered in over-browsed areas." It is apparent that there is dis- 
agreement as to whether or not barking is indicative of over-browsing. 

4. Percentage of Stems Killed Per Acre 

Birch, mountain ash and maples showed a decreased percentage 
killed on Shakespeare Island in the 1969 study (Table IV). On Kelvin Island, 
birch experienced a higher percentage killed than in 1964. Killed mountain ash 
also increased on Kelvin Island with 5.7% killed in 1964 and 77.8% in 1969. The 
kill of maples was about 50% greater in 1969 on Kelvin Island. 

Balsam fir, as in 1964, was only killed rarely in 1969. The kill 
rate rose slightly from 0.3% in 1964 to 0.4% in 1969 on Shakespeare Island. A 
greater increase resulted on Kelvin Island with 0.0% killed in 1964 and 1.5% in 
1969; this is not an important change, however. It is probably related to there 
being less deciduous browse on Kelvin Island and, therefore, greater use of balsam 
fir. 

As in 1964, several species were not in the killed column because 
they were not present. Cherries and hazel were absent from both islands during 
both surveys. Dogwoods seem to have disappeared from Kelvin Island since the 
1964 survey. Presumably they have been eradicated by moose browsing and/or forest 
succession. 

Of the three species listed in the killed column in 1969 for 
Shakespeare Island, an average of 23.5% of the stems were killed, compared with an 
average of 31.7% for the same three species in 1964. This suggests decreased 
browsing intensity and a lower moose population than in 1964. 

In 1964, there were six species represented in the killed column 
on Kelvin Island, with an over-all average of 21.0% of the six species being 
killed; the 1969 kill figure was 20.9%, indicating little change in percentage 
killed. 

The students recorded 11 stems on Shakespeare Island that had 
been "topped" (i.e. "straddled"). Of these, 7 were fir and 4 were cedar. Counts 
of straddled trees were not conducted in 1964. My impression, however, is that 
"topped" trees were more numerous in 1964. Paterson (1955:114) stated that the 
riding down of trees (straddling) is a habit of moose in areas of scarce food 
supply. If this is true, the lower number of straddled trees found in 1969 
suggests less of a food shortage on Shakespeare Island. 

In the British Columbia Wildlife Review (December, 1967), the 
author refutes the common belief that moose straddle trees. Instead, he claims, 
they break the stems with their strong jaws and powerful necks. These enable 
the moose to sever stems and branches more than one inch thick. The author does 
not indicate that there is any correlation between broken stems and a food 
shortage. 



32 



"Fresh" evidence of the presence of moose was greater in 1969 on 
Kelvin Island than on Shakespeare Island. Fresh tracks, pellet groups and recent 
browsing were more common on Kelvin Island. 

5 . Percentage of Hedged Stems 

In 1969, mountain ash and poplars were the most severely hedged 
species on Shakespeare Island; less hedging of ash occurred compared with 1964, 
but on Kelvin Island, ash was more hedged than in 1964. Hedging of balsam fir 
declined greatly from 46.9% in 1964 to 0.4% in 1969 on Shakespeare Island. These 
may be real differences in the rate of hedging of balsam fir. However, they 
suggest that there are differences in interpretation between the 1964 and 1969 
crews as to what constitutes a hedged balsam fir. If the differences between 
1964 and 1969 in hedging rates for balsam fir are real, then considerably less 
browsing pressure was indicated in the 1969 study on Shakespeare Island. 

On Kelvin Island, white birch, poplars and fir experienced less 
hedging in 1969, while maples were hedged more than in 1964. Four species were 
hedged in 1969, compared with six in 1964. 

6. Percentage of Available Browse Supplied by Each Species 

Of the seven species contributing browse on Shakespeare Island, 
five each contributed a greater percentage than in 1964 (Table IV) . Balsam fir 
and maples declined though in their contribution. The increases in amounts of 
browse supplied by birch, poplar and shrubs indicate less browsing pressure which, 
in turn, permits more regeneration of browse. 

On Kelvin Island, major increases occurred in the percentage of 
browse supplied by birch and balsam, but the contribution of deciduous browse 
species, in general, declined. Maples declined greatly (26.4%). This may be 
partially due to the increased mortality rate for maple observed in the 1969 
study . 

In 1964, five species each contributed 5% or more of the available 
browse on Kelvin Island, but in 1969 only two species (birch and balsam fir) 
contributed more than 5% of all browse. 



DISCUSSION AND CONCLUSIONS 

After analyzing the 1964 survey data, I became concerned about 
what the effects are on moose of an almost pure balsam fir diet. Shakespeare 
Island caused me the greatest concern, because 92 #9% of the available browse was 
composed of fir. There is even more fir on both islands now and deciduous stems 
will soon disappear; a result, primarily, of forest succession. Balsam fir will 
soon be the only browse species remaining. According to Peterson (1953) the 
general food habits of moose indicate that a variety of foods is an essential 
factor in a balanced diet. He also stated that a great quantity of poor foods or 
of only two or three species will apparently not maintain a healthy moose herd. 
He offered no analytical proof to support his beliefs. However, Bergerud and 
Manuel (1968) only partially agree with Peterson. In Newfoundland, they found 
that "moderately high" densities of moose and satisfactory productivity have 
been maintained for years with a population feeding on sufficient quantities of 
birch and fir in winter. They did not know then whether gross productivity of 
moose could be maintained when feeding solely on an adequate quantity of fir. 

33 



. t**> ■ * *• v •" 



Ri 

Simkin (1959) stated that the percentage of hedged balsam fir 
was a good indication of the quality of moose range. The poorer the range 
quality, he believed, the greater will be the degree of hedged balsam. If 
Simkin is correct, then the reduced hedging of fir on both islands in 1969 
indicates better range quality. 

Pimlott (1960) believed that balsam fir was only eaten in 
quantity by moose in areas of high moose density where the carrying capacity was 
reached or exceeded. Des Meules (1965) stated that balsam fir is a "good" food 
and its use is not necessarily indicative of poor range. Des Meules believed that 
heavy balsam fir utilization may have an important bearing on the energy balance 
of moose in late winter. Balsam fir, according to him, provides from 8 to 13 
times more browse per stem or twig than deciduous species. Therefore, on a 
100% balsam diet, moose would only have to browse 1/8 to 1/13 as many twigs as 
on a deciduous diet. Also, Des Meules states, the moose would have to walk less 
and spend only 1/8 to 1/13 as much time feeding. A great energy saving results 
as the animal will also be bedded longer. Only about 2 hours are spent feeding 
when feeding exclusively on fir. This suggests that balsam fir is nutritious 
and may even be superior to deciduous species as moose food. It is obvious that 
there is little agreement by the "experts" on the suitability of balsam as a 
browse species. 

Bergerud and Manuel (1968) found in Newfoundland that moose were 
able to select browse (fir) with high protein content. In view of our browse 
studies, it appears that moose can and do thrive on an almost pure balsam fir 
diet, especially on Shakespeare Island. For the last six years at least, and 
probably at least ten years, they have been limited to a mainly balsam fir diet. 
Chemical studies of balsam are required now by the Research Branch to determine 
the nutritional effects of fir on moose. If fir proves to be adequate then we 
should be thinking about the need for habitat manipulation which will exist in 
about 10 years, especially on Shakespeare Island because much of the present fir 
grows out of reach of moose. Conversion to conifers will be almost complete by 
then. Habitat manipulation would involve creating and maintaining various age 
classes of balsam so that continuous food and cover are provided. Experimental 
habitat manipulation is recommended now to determine the best size, shape and 
type of balsam habitat for moose. We should experiment with various silvicultural 
tools such as fire, herbicides and cutting to determine which is the best for 
creating and maintaining optimum moose range. There are some risks involved in 
managing the habitat purely for balsam. One is that there is not yet sufficient 
proof that moose can prosper indefinitely on a pure diet of fir. There may be 
unknown physiological effects (i.e. lowered reproduction) from this type of diet. 
Also, if some calamity strikes balsam fir (e.g. spruce budworm) , most or all of 
the browse and cover could be wiped out. The last outbreak of budworm was in the 
1940' s on the Lake Nipigon Islands. It was considered to be a serious infesta- 
tion. 

There would be advantages in habitat manipulation for fir. 
Balsam is abundant now and will increase for about 10-15 years. It regenerates 
easily and can withstand repeated and heavy browsing with little mortality of 
fir resulting (Bergerud and Manuel 1968) . Balsam fir provides food and excellent 
cover. Moose do not have to move far from cover to find food as they do when 
feeding on deciduous stems (e.g. as in a burned or cut-over area). 

There seems to be little use in attempting habitat manipulation 
for deciduous stems. Any increase in shrubs would be temporary because of natural 

34 



conversion of the stand to conifers. Most deciduous species, being intolerant, 
could not compete with the balsam. Also, deciduous species (e.g. maples, ash, 
willows) provide little browse per stem and are easily killed by browsing. 

There is, of course, the possibility that some deciduous regenera- 
tion will occur incidentally in habitat manipulation for balsam. Poplars and 
birch will likely provide coppice growth, but this growth will not persist for 
long because of the forest succession factor. An increase in birch and poplars 
might result in a temporary increase in beavers and ruffed grouse. 

Pellet Group Studies 

Moose pellet group counts were recorded while the browse surveys 
were conducted. A defecation rate of 13 times daily was used. In mixed woods, all 
pellet groups lying on top of the leaves were recorded as they were assumed to have 
been deposited since leaf fall. In coniferous areas, ageing of pellet groups was 
accomplished by colour and texture. 

The plot size was 1/50 acre and the strip width 13.2 feet or 6.6 
feet on each side of the chain. From leaf fall (October 20) to completion of 
the survey on Shakespeare Island, approximately 215 days elapsed and 217 days on 
Kelvin Island. Only two pellet groups were recorded on the plots on Shakespeare 
Island, compared with 56 groups in 1964. On Kelvin Island, 28 groups were recorded 
compared with 48 in 1964. 

Calculations from Pellet Group Counts 

1 . Shakespeare Island 

(a) Average number of pellet groups per acre calculated as the 
average count per plot x 50. 

Average Count per Plot = 2 Pellet Groups per Acre = 26 x 50 

64 64 

(b) Moose days per square mile, calculated as: 

Pellet groups per acre x 640 or _2 x 50 x 640 
Deposition rate (13 times daily) 64 13 

(c) Moose per square mile, calculated as: 

Moose days per square mile or 2 x 50 x 640 = 1000 - 0.358 = 0.36 = 0.-+ 
Number of days of pellet deposition 64 x 215 x 13 2795 



2 . Kelvin Island 



(a) Average number of pellet groups per plot = 2_8 

64 
Pellet groups per acre = 28 x 50 

64 

(b) Moose days per square mile = 28 x 50 x 640 

64 13 

(c) Moose per square mile = 28_ x 50 x 640 = 4.962 = t.^o = 5.0 

64 217 13 

35 



DISCUSSION AND CONCLUSIONS ON PELLET GROUP STUDIES 

The 1969 pellet group counts reflect the decline in moose since 
1964 on the two islands. Pellet group counts on Shakespeare Island indicate an 
almost 2700% decline in moose since 1964, while the 1968-69 aerial count indicated 
a 2400% decrease in moose. Relatively close correlation exists between estimates 
from pellet and aerial counts as to the existing moose population during the 
winter of 1968-69. 

The Kelvin Island pellet count suggests the moose population is 
59% less than in 1964 but the 1968-69 aerial count suggests that the herd was 
only at 13.9% of its 1964 level. The Kelvin Island study suggests that there were 
more moose on the island during the 1968-69 aerial survey than were seen. However, 
there could have been an ingress of moose onto Kelvin Island after the aerial 
survey. Or the Kelvin Island browse study area could have been a winter concentra- 
tion area; this would result in a concentration of pellet groups. No evidence 
exists that the study area was in such a moose concentration area. 

MOOSE MANAGEMENT 

Prescribed burns should be used in experimental habitat manipula- 
tion for balsam fir. The importance of fire in creating good moose habitat was 
reported by Aldous and Krefting (1946) . Some plots should be cut first and then 
burned. Others should be burned only to determine which is best to stimulate 
balsam regeneration. Except experimentally, clear cutting is not recommended. 
The cost would be prohibitive and it would be impractical to treat large plots 
(e.g. up to 30 acres). 

Partial or selective cuts may be adequate to perpetuate fir. 
Removal, periodically, of some large age classes of fir may be adequate to maintain 
various successional stages of the species. However, it seems likely that growth 
of young balsam would be stimulated due to a reaction to exposure (Bakuzis and 
Hansen 1965) . The young balsam would grow out of reach faster as a result and may 
actually contribute to an accelerated browse shortage in later years. We should 
experiment with chemical control of balsam fir. Bakuzis and Hansen (1965) report 
that balsam fir is a "hard to kill" species using herbicides. If a selective 
herbicide is available, chemical control should be considered. 

There is no reason why moose on Shakespeare and Kelvin Islands 
should not increase now that the season is closed for 1970. Hunting appears to 
have been the main limiting factor. If given sufficient time, the herds probably 
would re-build to near their 1964 levels. However, sustained populations at or 
near their 1964 level are not desirable or possible. Range damage would be 
severe in a short time. We must determine what the carrying capacities of the 
islands are and try to maintain the moose herd at their carrying capacities. 

The Lake Nipigon Islands are a unique and valuable management 
unit. The total area of the islands is about 229 square miles and the water surface 
area of Lake Nipigon is 1530 square miles. It is the largest inland lake in Ontario 

The islands are easily accessible by boat or by aircraft. Hunting 
for moose is mainly done from a boat, by hunting along the shoreline or by sitting 
in bays and around the shore of the inland lakes of the islands. Few hunters 
walk the islands because of the thick balsam fir and rugged terrain which makes 

36 



stalking moose almost impossible. Most of the people who hunt the islands are 
non-residents and guests of the eight tourist outfitters on Lake Nipigon. An 
estimated 80% of the legal moose kill is by the parties of outfitters. It is 
estimated that the non-resident moose hunt on the islands is annually worth 
about $20,000.00 to Ontario. This money is derived from licences and goods and 
services. An unknown number of residents from Thunder Bay, Nipigon, Cameron 
Falls, Gull Bay and other communities also hunt the islands and contribute a 
great deal of money to the local economy. It is obvious that the consumptive 
value of the Lake Nipigon herd is great and may well range to 30-40 thousand 
dollars annually, exclusive of the value of the moose meat. 

The Lake Nipigon moose herd has immense non-consumptive (aesthe- 
tic) value also. Moose are frequently seen on the shore by anglers and cottage 
owners and are a highlight for most people. This adds to the immense over-all 
value of the herd and is a further reason why it must be perpetuated. It is 
obvious that the Lake Nipigon moose herd cannot withstand unlimited hunting 
pressure (i.e. uncontrolled kill). There will have to be some regulation of the 
kill in the future. The harvest should be confined to the annual surplus, which 
should be determined. Once kill of the annual surplus is achieved, the season 
will have to be terminated immediately for that year. This would require a 
flexible legal basis that permitted a quick response of hunting regulations to 
the needs of management (i.e. immediate closure of the season at the District 
level) . 

Zoning might be used effectively on the islands to regulate the 
kill. For example, the moose season could open from October 15 to October 31. 
The rut would be over by October 15 and bulls, especially, would be less vulner- 
able as they would not be easily "called" to shore. Fewer bulls would be shot 
as a result. This type of zoning, though, would almost definitely limit the 
hunt to parties of tourist outfitters and those with large boats. By October 15, 
Lake Nipigon is extremely unpredictable and usually too rough for small boats. 

When the season is re-opened, if we permit a continued unlimited 
kill, it is inevitable that we will be faced with open and closed seasons to 
re-build the herd. This may be more simple to administrate than zoning or 
regulating the kill. But closed seasons do not bring revenue to the area and, 
I think, are an unsatisfactory way of "managing" moose. 

To incorporate zoning or regulating the harvest would involve 
the need for intensive public relations work to enlist support of outfitters, 
sportsmen's groups, etc. If properly "sold" to the people, they would probably 
actually support a more sophisticated moose management effort on our part. 

Future land use plans (20-30 years in the future) indicate that 
the primary value of the islands will be for wildlife management and recreation. 
Most of the islands are Crown Land and would be open to experimental management. 
There is little, if any, possibility of commercial logging during the next 30 
years. We would, therefore, be in an excellent position to experiment with 
habitat manipulation, population manipulation, etc. Changes in the moose herd 
should be easy to monitor because of the relative "isolation" of the herds. 

RECOMMENDATIONS 

(1) We should experiment now with habitat and species manipula- 
tion so that we will be prepared for intensive range management in the next 10 
to 15 years. We must prepare the people now for the need for a regulated harvest 
and any changes (e.g. zoning) that may be necessary. 

37 



(2) Pre -treatment and post -treatment studies should be carried 
out on the areas to be cut, burned or chemically treated and results assessed. 
Control plots should be established to determine the effectiveness of the program. 

(3) Intensive ecological studies should be conducted on the 
islands. Congregation areas of moose (if any) should be mapped from the air and 
studied on the ground; moose movements should be studied (probably by radio 
collaring and tag and recovery information) . The effects of wolves should be 
studied and wolf -killed moose inspected at every opportunity. Annual aerial 
inventories will be required to adequately monitor population changes. Browse 
surveys should be conducted every three years to determine when intensive habitat 
manipulation will be needed. Studies of diseases and parasites and reproduction 
should be conducted. Summer range (especially aquatic plants) should be studied 
to see if there is a shortage. 

(4) Commercial logging should be permitted if there is an 
application to cut. Control should be strict so that wildlife and aesthetic 
values are best served. 

(5) The Research Branch should determine whether balsam fir 
provides a nutritious diet for moose and whether it produces subtle physiological 
changes (e.g. reproductive changes). Defecation rates of moose as they vary with 
diet, time of year and age and sex should be studied by the Research Branch. 

(6) An intensive collection of hunt data is needed annually such 
as collecting jaws, plotting kills by time and location; effects of weather on the 
kill, numbers of hunters (both resident and non-resident). 

(7) We should determine the socio-economic importance of the 
Lake Nipigon moose herd. Cost/benefit analyses should be conducted for any 
proposed or completed projects so that maximum benefits can be achieved. 

SUMMARY 

Moose browse and pellet group studies were conducted during 1969 
on two islands of Lake Nipigon. Results were compared with similar studies 
carried out in 1964. There is no shortage of browse on either island. Natural 
factors (e.g. egress of moose, mortality and range conditions) do not seem to be 
responsible for the decline in the moose population. An over-harvest by hunters 
is the apparent cause of the decline. 

Balsam fir increased in abundance on both islands. It contributed 
85.6% of all live browse stems per acre on Shakespeare Island and 56.8% on Kelvin 
Island. There are more live browse stems of all species per acre on Shakespeare 
Island than in 1964; no increase in browse stems occurred on Kelvin Island. 
Browsing pressure is less on both islands compared with 1964; the hedged and 
killed rate for many species is also less. 

Experimental habitat manipulation, intensive ecological studies 
and a regulated harvest are recommended in managing the Lake Nipigon moose herd. 
Nutritional studies of balsam fir are required to determine its long term 
effects on moose. Cost/benefit analyses should guide management efforts. 



38 



re: * y 

LITERATURE CITED 

Aldous, S. E. and L. W. Krefting. 1946. The present status of moose on Isle 

Royale. Trans. N. Amer. Wildlife Conference for the year 1946. 
American Wildlife Institute, Washington, D. C. 

Bakuzis, F. V. and H. L. Hansen. 1965. Balsam fir. A Monographic Review, 
Univ. Minn. Press. 445 pp. 

Bergerud, A. T. and F. Manuel. 1968. Moose damage to balsam fir-white birch 
forests in Central Newfoundland. Jour. Wildlife Mgmt . 32(4): 
729-745. 

Candy, R. H. 1938. Growth and regeneration surveys in Canada. Bull. For. 
Serv. Canada. No. 90. 50 pp. 

Des Meules, Pierre. 1965. Hyemal food and shelter of moose in Laurentide Park, 
Quebec. Master of Science Thesis at Guelph University. 138 pp. 

Gibson, B. H. 1964. Moose browse and pellet group surveys on two islands of 

Lake Nipigon, 1964. Unpublished Report, District Office Files. 

Murie, A. 1934. The moose of Isle Royale. Misc. Pub. Mus. Zool., Univ. 
Michigan, No. 25. 44 pp. 

Peterson, R. L. 1953. Studies of the food habits and habitat of moose in Ontario 
Royal Ont. Mus. Zool. and Paleont/Contrib. 34. 30 pp. 

Peterson, R. L. 1955. North American moose. Univer. Toronto Press, Toronto, 
Ontario. 280 pp. 

Pimlott, D. H. 1961. The ecology and management of moose in North America. 
La Terre et la Vie, No. 2, 1961. pp. 246-265. 

Simkin, D. W. 1959. Big game browse and pellet survey in the Sioux Lookout 
District. Ont. Dept . of Lands and Forests, Resource Mgmt. 
Report No . 46 . 



39 



THE LAKE STURGEON ( Acipenser fulvescens ) 
OF LAKE NIPIS SING—A PRELIMINARY REPORT 

by 

JAMES K. YOUNG, Biologist 
GEORGE F. LOVE, Fisheries Management Officer 
North Bay District 



ABSTRACT 



During the past half century, there have been 
drastic changes in the size and age structure of the 
Lake Nipissing sturgeon population. The causes 
include loss of spawning grounds, fishing pressure, 
and lengthening of seasons. The sturgeon is especi- 
ally vulnerable because of its characteristics of 
being late in maturing and having a long life span. 

A brief history of the commercial sturgeon 
fishery is presented. The sturgeon spawning 
success has dropped considerably during the past 50 
years. The major cause is probably loss of spawn- 
ing grounds including the Sturgeon River which used 
to be the most important. Some spawning still takes 
place as the smallest sturgeon on record (3" long) 
was taken from the lake this summer. 

From tagging done on undersized sturgeon 
(1960-63), it was determined that the fish may 
cover long distances in a short time. Yellow 
streamer tags were attached in front of the dor- 
sal fin. There was evidence of tag loss with 
time. When further tagging was carried out in 1970 
with monel metal jaw tags, only five undersized 
sturgeon could be caught. One was recaptured. 

From the tagging data, five estimates were 
made of the size of the population of undersized 
sturgeon which indicated approximately 10^ fish. 
Since 1960, there has been a trend towards larger 
and fewer undersized sturgeon which verifies the 
noted decrease in spawning activity. 

A growth curve was established from 32 
sturgeon by counting annuli in cross sections of 
the first ray in the pectoral fin. A technique 



40 



for preparing permanent sections embedded in 
plastic was developed and the annuli were 
counted tinder a binocular microscope. From 
the 32 sturgeon studied, there were only 3 
males . 



INTRODUCTION 

Surprisingly little work seems to have been carried out on the 
lake sturegon in Lake Nipissing even though this species is of a great commercial 
value in that lake. In 1970, the Fisheries Management Unit undertook to gather 
information on this fish. The commercial fishermen were instructed to tag under- 
sized fish and to save pectoral fins (for aging) together with lengths, weights, 
etc. of their legal sized sturgeon. 

This report is a summary of the data collected during the current 
survey as well as the results of previous records. 

COMMERCIAL FISHING FOR STURGEON 

There has been commercial fishing on Lake Nipissing for over 100 
years. At first, gill netting would seem to have been the most important method. 
Although fishery records date back to 1885 (Harkness 1936), it was not until 
about 1900 that the fishery was really opened (Harkness and Dymond 1961) . In 
1908, the use of gill nets was outlawed. From that year to 1917 inclusive, 
sturgeon fishing in Lake Nipissing was closed. The records for sturgeon 
catches prior to 1917 are rather spotty (and likely unreliable) . 

In 1914, during the closed period, the first pound nets were set 
on the lake with specialists being called in from Germany to help. Since the 
opening of the pound net fishery in 1918, accurate records of the number of 
pounds of dressed sturgeon taken each year have been kept. These together with 
the less accurate information for the period prior to 1918 appear in Graph I. 

As can be seen from Graph I, catches of sturgeon were very high 
for the first few years that pound nets were used but decreased rapidly so that 
by 1929 only 2980 pounds were taken. Since that year, catches have fluctuated 
between 4000 and 15,000 dressed pounds per year. 

Prices received for the fish have increased steadily in the past 
twenty years from $1.50 per pound ($2.50 for caviar) in 1952 to $1.95 per pound 
($4.80 minimum to $18.00 per pound for processed caviar) in 1969. The two 
commercial operators reported fish sales amounting to about $30,000.00 in 1969. 
Of this over $21,000.00 or 70% resulted from the sale of sturgeon and caviar. 

There are two Indian reservations on the lake. Number 10 (#10) 
on the north shore extends from just east of Sturgeon Falls to the west end of 
Commanda Township. The Dokis reserve (#9) on the French River lies between the 
Little French River and Chaudiere. The people of these reserves have always 
taken some sturgeon by spearing, hook lines, and gill nets but there are no 
records of harvests or of the pressure exerted by this fishery. 



41 





















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1950 



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1930 



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1920 







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1910 



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42 



In the past, there have been closures on the sturgeon fishery 
presumably to protect the ripe fish until they had spawned. In 1903, an Order 
of Council prohibited fishing for sturgeon during the months of May and June. 
In 1927, this closure was reduced to June only. In 1953, this restriction, too, 
was removed. From Graph II, it can be seen that during the 1960-63 tagging 
study, June and July were by far the best months for taking undersized sturgeon 
(and probably also legal sized fish). Thus, during this period, 1903 to 1953, 
the seasonal ban on fishing likely restricted the catch considerably. 

There have always been only the two commercial ventures on the 
lake. Up to 1963, the licences governing the fishing restricted the two opera- 
tors to six and eight nets respectively. In 1963, the one fishery was allowed 
a seventh net . 

Over the years, the net sites have varied greatly as allowed by 
the licences. The net sites are defined as follows: 

(1) Four nets to be set fronting the Township of Springer 
between a point 2,760 yards east of the mouth of the Sturgeon River and the 
western limit of the Indian Reserve #10; and three nets set off the north shore of 
Sandy Island. 

(2) Five nets to be set between the boundary of Indian Reserva- 
tion #10 and a line drawn five miles east thereof. Three nets to be set in the 
waters fronting Lots 12, 13, and 14 in the Township of Caldwell, extending south 
to the north shore of these Islands in a south easterly direction to a point 
where it intersects an extension of the boundary line between Lots 12 and 13 of 
Springer Township. 

SPAWNING 

Most reliable sources seem to agree that the sturgeon is much 
less successful in its spawning attempts than it was previously. In 1960, Mr. 
Jim Gage, then North Bay District's Biologist, interviewed a number of older 
residents on this subject. The following are the results of his findings: 

Interviewee: Mr. George Collins, Sturgeon Falls --Mr. Collins 
stated that he had worked for several of the commercial fishermen in Lake 
Nipissing and remembers that they sent to Germany for guidance as no one knew 
how to set a pound net. A Mr. Adam Reid and a Mr. Leonard White arrived to show 
them how to set this gear. This was about 1914. Fishing for sturgeon was 
exceptionally good and a refrigerator car and a refrigerator scowwereused to 
handle the large quantities of fish. Six men were employed to dress out the 
catch while three more buried the offal including tubs of the now valuable caviar. 

Mr. Collins also remembered that the Sturgeon River from the 
town to the mouth was laced with hook lines. These lines were not baited. It 
was also the practice of local townspeople to fasten a number of hooks to a 
weighted line and jib or snag sturgeon from the river. 

Mr. Collins feels that a few sturgeon still come up the river to 
spawn, but he states that in the old days, one could leave the bedroom window 
open at night and hear the sturgeon as they jumped and splashed in the pool below 
the falls. Sturgeon were never known to gain access to the river above Sturgeon 

43 



NO. ( 


)F STURGEON 


TAGGED 


EACH 


MONTH DURING 


THE 


I960- 


•63 STUDY 










1960 




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1961 
1962 
1963 











fa 
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OS 

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60616263 


60616263 


60616263 


60616263 


60616263 


60616263 


MAY 


JUNE 


JULY 


AUGUST 


SEPT. 


OCT. 



44 



Falls. A large boat, which travelled Lake Nipissing for years, named the 
"Katherine C" manned by a Captain Gildy, was originally built to carry sturgeon 
catches. The largest sturgeon he ever witnessed weighed 190 pounds. He believed 
sturgeon spawned June 1 to 15 . 

There were always lots of ling and sheepshead in the catch. 
Very few black suckers but lots of redfin suckers. Mr. Collins knew and worked 
for such commercial men as Cockburn, Hatch, Laing, and Livingston. He cited the 
observance of sturgeon being taken from the pound nets with clay and sand still 
sticking to their bodies. His opinion was that they had come from deep water 
where pound nets could not be set. The usual price of sturgeon was 30c per 
pound for males and 40<£ per pound for females. He believes the present sturgeon 
population is adversely affected by the Chaudier Dam on the French River and 
that the free access in the old days permitted sturgeon to come upstream into 
Lake Nipissing. 

They fished such locations as Dokis Point, Jocko Point, Indian 
Village and Pine Island. Mr. Collins was not conversant with the present situa- 
tion. His statements regarding the sturgeon were entirely unbiased and not 
connected with the present in any way. 

Interviewee: Mr. Hector Renaud, Laronde Creek, Meadowside - -Mr . 
Renaud felt that some sturgeon still come into the Little Sturgeon River to spawn 
at the "First Slide" but due to the present water conditions, the foam prevents 
them from being observed. It was his opinion that the increase of outboard motor 
activity has frightened off the sturgeon. He states that a large number of 
sturgeon were dynamited at the slide about 1930 and large numbers were observed 
floating down the river. Mr. Renaud owns a farm near the first slide and has 
logged the immediate area for many years. He reported that even as late as 1942 
the Abitibi Company at Sturgeon Falls always notified the local Game Warden when 
they were going to shut down to reserve water supplies. This often left large 
sturgeon stranded in shallow pools and at the mercy of poachers. Mr. W. J. 
St. Pierre, Conservation Officer at Sturgeon Falls, substantiated this statement 
but has not been notified in recent years because of the lack of sturgeon in the 
river. Mr. Renaud felt that the large amounts of wood fibre found at Sturgeon 
Falls discouraged spawning sturgeon. He noted that sturgeon usually spawn when 
the poplar leaves have fully emerged and begin to shake. He believes some spawning 
takes place in the lake near the mouth of Laronde Creek. 

Interviewee: Mr. Dave Coventry, Sturgeon Falls --Mr. Coventry 
worked with commercial fishermen fishing sturgeon from Nipissing in past years. 
He claimed sturgeon jumped night and day in June and July below the falls at 
Sturgeon Falls. He had never seen fish spawning in Lake Nipissing. He, too, 
felt that June was the time of spawning. He was much concerned with the decrease 
in numbers of sturgeon compared to years as recently as 1945. He also felt that 
pike and pickerel were decreasing in numbers. This man appeared somewhat biased, 
and we had difficulty in keeping the interview limited to sturgeon. 

Interviewee: Mr. Rene Moerman, Laronde Creek Lodge, Meadowside -- 
Mr. Moerman recalls large spawning runs in the Little Sturgeon River and even 
some fish in Laronde Creek. He recalls dead sturgeon as a result of dynamite 
referred to by Mr. Renaud. Mr. Moerman stated that local Indians claim there were 
always two runs but he only ever saw one run, about the time the poplar leaves 
emerge. He has seen the odd sturgeon recently at the first slide on the Little 
Sturgeon River. He notes concentration of sturgeon in Lake Nipissing and jumping 
fish around Beaucage Point and Jocko Point. 

45 



Although Mr. Moerman operates a boat livery on Laronde Creek, 
he too suggests that the constant activity of outboard motors in Laronde Creek 
and the Little Sturgeon River has discouraged the sturgeon during the spawning 
season. 

Summary --None of the interviews revealed any obstructions in the 
rivers except the Chaudier Dam--outlet from Lake Nipissing. Sturgeon apparently 
spawned below the falls or slides in the river and could be seen in pools below 
such water turbulence. All agreed on spawning time as early June. Reasons 
given for decrease of numbers were fibre from pulp company, outboard motor 
activity and heavy fishing in the past. 

According to most people, things have become even worse during 
the last decade. Both commercial operators say that they have noticed a sharp 
drop in the number of undersized sturgeon caught in their nets (illustrated by 
the current tagging project as compared to the 1960-63 study) . 

Also, little spawning activity has been noted in recent years. 
The Sturgeon River seems to have decreased to zero importance as a spawning area 
for this species. The bottom is completely covered in wood fibers and pulp and 
the water is very turbid with suspended material. 

However, some spawning activity is still taking place as recently 
a small sturgeon, about 3 inches in length, was taken from Lake Nipissing. 
This specimen is much smaller than the smallest one reported by Harkness (1960) 
as being 5.7 inches. Our specimen, when caught, was quite translucent with a 
distinct black saddle behind the head and a second near the base of the tail. 



MOVEMENTS 

From 1960 to 1963, an initial project was undertaken by the 
Department to study the movements of the sturgeon in Lake Nipissing. The 
commercial fishermen co-operated by tagging undersized fish*, which they caught 
in their pound nets. 

Tags used in this study were of the yellow streamer type and 
were secured immediately in front of the dorsal fin. The fishermen kept records 
of tag number, total length of the fish as well as the location and date of 
tagging. 

During this study, 217 sturgeon were tagged. Table I shows 
the number of fish tagged at each net location per month for each year. 

Cockburn Bros, sold out to Paul Benoit in 1963 and no tagging was 
done by this fishery in this summer. The total number of sturgeon tagged by each 
operator in each year is shown in Table II. 

It was evident from this study that at least some of the fish 
were losing their tags. At least three were recovered that had tag scars. Also 
from the table of recaptures (Table III), it can be seen that no tagged fish was 
recaptured more than three years after it had been tagged and none were recaptured 
after 1964. 



* To be legal in Lake Nipissing, a sturgeon must be at least 25 inches from the 
most posterior limit of the gill opening to the point where the posterior edge of 
the dorsal fin joins the flesh of the body. 

46 



TABLE 


I 


























































NO 


. OF 


FISH TAGGED AT 


EACH 


NET 


LOCATION 
























DURING 


EACH 


MONTH 


OF 


EACH YEAR 


FROM 


1960 


TO 


1963 




















1960 










1961 










1962 










1963 






NET 


M 


J 


J 


A 


S 





M 


J 


J 


A 


S 





M 


J 


J 


A 


S 





M 


J 


J 


A 


S 





Tl 




3 


1 


1 










2 








1 


4 










3 


4 


3 








2 




2 












5 


10 




1 






1 


1 






1 


6 


2 


6 








3 




2 


1 






1 




6 


5 






1 




2 


1 








5 


1 


7 








4 








1 






1 


2 


2 


1 


1 






3 


3 




5 


1 


1 


3 


4 


1 


1 




5 




4 








1 




1 


2 


1 


2 


1 


1 


3 












14 


7 


5 


1 




6 






1 




2 




4 


9 
1 


3 
5 


2 


1 
1 


2 


1 


6 


4 




2 






5 


2 




2 




CI 






1 


2 


1 






1 


1 










1 


1 




















2 


















































3 








1 






















1 




















4 






























1 




















5 


















1 
































6 






2 


1 




















2 






















7 
















2 


6 


3 








1 


1 




















8 
















6 


6 


5 






























TOTAL 





11 


6 


3 


3 


2 


5 


33 


43 


12 


6 


4 


2 : 


23 


16 





7 


2 


15 


29 


29 


6 


4 





TABLE 


II 

















































NO. OF STURGEON TAGGED EACH YEAR 
OF THE 1960 TO 1963 STUDY 



YEAR 



NO. TAGGED 
BY TAILLON 



NO. TAGGED 
BY COCKBURN 



TOTAL 
NO. TAGGED 



1960 
1961 
1962 

1963 



21 
65 
40 
84 



8 
39 
10 
No Tagging Done 



29 

104 

50 

84 



47 



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48 



Apparently sturgeon move around a great deal (Recapture Map 
omitted). Of the twenty recaptures, only one was made in the same net in which 
it had been tagged. Movements appear to be quite random (i.e. there is no 
definite seasonal migration as found in such fish as the pickerel and cisco) . 
One recapture showed that sturgeon may cover large distances in short periods of 
time. This fish moved a distance of 6.25 miles in five days. 

Another fish, tagged in September of 1961, was speared by an 
Indian less than one year later in the free flowing channel of the Little French 
River, more than 25 miles away. This is an indication that sturgeon may wander 
to a much greater extent than is indicated by the recaptures. The location of 
the pound nets was a limiting factor to a measurement of the extent of movement . 
The greatest movement possible between pound nets is a distance of approximately 
ten miles. Map 1 shows that fraction of Lake Nipissing which is commercially 
fished . 



MAP 1 



Sturgeon Little 
River Sturgeon 
River 



Laronde 
Creek 




LAKE NIPISSING 



Another project of the same type as the 1960 to 1963 study has 
been started. However, this year the fishermen employed monel metal jaw tags, 
the same kind that we have been using in our pickerel project. One fishery 



49 



(Art Taillon) has co-operated. However, to date he has caught only five under- 
sized sturgeon. Of these, he has recaptured one (tagged June 22, 1970, at Sandy 
Island; recaptured July 22, 1970, on the North Shore). 

SIZE AND STRUCTURE OF THE POPULATION 

It is possible using the standard mark-recapture method and the 
data from the 1960 to 1963 tagging study to get estimates of the population size 
(of undersized sturgeon only). There are many arguments against using this 
method in this instance: 

(1) We do not know the rate of natural mortality and/or fishing 
mortality in the sturgeon population and therefore the estimates can not account 
for this. 

(2) Some fish have almost certainly lost their tags even after 
one year; and it looks like most have lost them after three years. 

(3) The method of estimating assumes that tagged and untagged 
fish are equally likely to be caught. 

(4) The method also assumes that the undersized sturgeon move 
freely about the lake. If this assumption is wrong, the estimate is only good 
for that unknown area through which the fish distribute themselves. It is known 
that the sturgeon is found throughout the lake--i.e. they have been caught by 
anglers in the Upper French, in North Bay, at the Manitous and in South Bay; 
however, whether there is free mixing of fish from these areas and those in the 
commercial fished area is not known. 

In spite of these problems, an estimate using the mark-recapture 
method may still be of some value as an index of the population size. 

Estimates : There are two ways of estimating population size from 
the 1960-1963 data by grouping the information differently (data of Table III) . 

Method I 

Using information from two successive years only. Utilizing 
this method, one has to worry about natural mortality over only a one year 
period. 

1(a) In 1960 tagged 29 undersized sturgeon. In 1961, tagged 
104 more and also recaught 2 of the 1960 fish. 

.«. estimate 1(a): 

# of 1960 fish recaught in 1961 = # of untagged fish in 1961 
# tagged in 1960 estimate of pop. 

.♦. estimate 1(a) = 104 x 29 = 1508 

2 



50 



1(b) In 1961 tagged 104 undersized sturgeon. In 1962 tagged 
50 more and also recaught 3 of 1961 fish. 

/. estimate 1(b) = 104 x 50 = 1735 

3 

1(c) In 1962 tagged 50 undersized sturgeon. In 1963 tagged 
34 more and also recaught 2 of 1962 fish. (N.B. — Taillon's fishery only) 

.*. estimate 1(c) = 34 x 50 = 850 

2 

Method II 

Using recaps from one year with tagging information from all 
previous years. Using this method, total mortalities will differ between 
estimates and also for groups of fish within an estimate. On the positive side, 
by using this method, one is dealing with larger numbers of both recaptured and 
tagged individuals. 

11(a) By the beginning of 1962 had 29 + 104 = 133 undersized 
sturgeon tagged. In 1962, tagged 50 more and also caught 4 previously tagged 
fish. 

.'. estimate 11(a) = 133 x 50 = 1663 

4 

11(b) By the beginning of 1963, had 29 + 104 + 50 = 183 under- 
sized sturgeon tagged. In 1963, tagged 34 more and also caught 4 previously 
tagged fish . 

.-. estimate 11(b) - 34 x 183 - 1500 

4 

Thus the five estimates are 1508, 1735, 850, 1663, and 1500. It 
is felt that these estimates should not be compared statistically since different 
data was used to arrive at each one. Nevertheless, the relative closeness of 
these estimates would seem to indicate that the number of undersized sturgeon 
available to the fishery (in 1960-63) was not too unlike the estimates. 

The above estimate would appear to be quite a bit greater than 
the present population number. Art Taillon has caught only 6 undersized sturgeon 
so far this season. Five were tagged and released. (One was given to the Parks 
Branch to put into the fish pond at Marten River Provincial Park.) 

Graph III shows the length frequencies of the 217 undersized 
sturgeon tagged during the 1960 to 1963 study. As can be seen from this graph, 
the greatest number of fish are undersized by only a few inches--there are very 
few that are more than ten inches undersize . 

On Graph IV, the data of Graph III has been broken up into years 
of tagging. From this graph, it can be seen that there seems to be a trend even 
from 1960 to 1963 towards larger fish. Also, from this graph there appears to 
be strong and weak year classes. For example, in 1960 there seems to be a mode 
at 31-32 inches; in 1961 at 36-37 inches; in 1962 at 39 inches and in 1963 at 40- 
41 inches. However, to verify this, much more information will be needed on 
growth rates, etc. 

51 





CM 



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eg 



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(Number of Individuals) 



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52 



RESOUR 



S LIBRARY 



GRAPH IV 

LENGTHS OF UNDERSIZED STURGEON 
TAGGED IN LAKE NIPISSING EACH YEAR 
OF THE 1960 TO 1963 TAGGING PROJECT 



•i""!"! 



1963 



13 



18 



23 



28 2930 3132 33 34 36 37 38 39 40 4142 43 44 46 
LENGTH (INCHES) 



1962 



28 31 32 33 34 35 36 37 38 39 40 41 42 



18 



23 



46 



7TT 



t'J'.'-'i 



1961 



13 



13 



18 



23 25 27 



31 32 33 34 35 36 373839 4041 42 



19 22 2324 26 29 303132 33 34 35 3637 38 

53 



46 















•'.'•' 










I960 




;.;.;• 






:':::' 






.;-. 




:::: 




.... 






m 





46 



Mr. Taillon is presently searching in his older shipping records 
to find out the numbers of fish shipped each year. If this information is 
available for the 1960-63 period, one could statistically compare the ratio of 
undersized fish; legal sized fish caught by the fishery in the 1960-63 period to 
that of 1970. Also, this data together with the Department's records of total 
harvest each year (in dressed pounds) could be used to determine average weights 
for each year. If spawning is becoming less and less as it would seem (and thus, 
the proportion of undersized sturgeon in the fishery decreasing) then the average 
size of legal sized fish should be increasing. It is hoped that these possibili- 
ties may be investigated and published in the near future. 

SEX RATIO 

During the 1970 season, Mr. Art Taillon has provided the 
Department with good information on 32 sturgeon. Of these, all but three were 
females. Both Mr. Taillon and Mr. Benoit state that as long as they have fished, 
females have always outnumbered males about 10 to 1 . Mr. J. K. Harkness and 
J. R. Dymond (1961) report that "information suggests that in the young the sexes 
are approximately equally numerous but among the largest and oldest sturgeon there 
is a preponderance of females." This means that on the average, females live 
longer than males. 

AGE ANALYSIS AND GROWTH RATE 

1 . Introduction 

This section is based entirely on data collected during the 
current season (1970) . The co-operation of the two commercial pound net fishermen 
was depended on for the collection of material. They were instructed to remove 
a pectoral fin at its base from each legal sturgeon, place it in a plastic bag, 
and attach a tag containing the following: total length, sex, date caught, and 
location where caught. These samples were then to be frozen immediately and kept 
frozen until they were picked up. To date, Mr. Arthur Taillon of Sturgeon Falls 
has been most co-operative in this study, having supplied 32 complete samples. 

2 . Method of Preparing Permanent Fin-Ray Sections 

The primary ray of the pectoral fin was removed with a knife by 
cutting between it and the second ray to near its base and then bending it back 
to free it at the bottom. These operations could be accomplished with little 
effort even when the fin was still frozen or partially frozen. No further 
cleaning, other than rinsing off any slime, was required prior to drying the ray. 

An adequate method of marking rays was essential so that they 
could later be matched to the corresponding information cards. 

When a small number of rays were to be dried at a given time, 
they were laid out in order on a metal tray and the cards were laid out in the 
same order on a table. The rays were dried by placing the tray in an oven at 
225° F for thirty minutes. Care was taken not to overheat the rays as this tends 
to harden and discolor them so that they become brittle to cut and extremely 
difficult to read (the same problem apparently arises when a power saw is used to 
cut sections) . 



54 



TABLE IV 



INFORMATION FOR 29 g STURGEON AND 3 o* STURGEON 
- TAKEN IN 1970 IN COMMERCIAL POUND NETS 



AGE 



LENGTH 



WEIGHT 



DATE CAUGHT 



LOCATION 



? 



13 


41 


15 


44 


16 


43.5 


17 


50 


17 


43.5 


17 


43 


17 


48 


17 


52 


18 


48 


18 


46 


18 


49 


19 


51 


19 


44.5 


21 


44,5 


21 


51.5 


22 


51 


23 


58 


24 


57 


24 


54 


27 


61 


27 


59 


29 


61 


31 


63 


31 


62 


31 


63 


33 


53.5 


35 


65 


48 


61 


50 


66 


15 


45 


16 


43 


21 


45 



19 


July 


27 


Sandy 


Island 


20 


August 


3 


North 


Shore 


25 


June 


1 


Sandy 


Island 


29 


August 


3 


Goose 


Islands 


25 


June 


26 


North 


Shore 


20 


June 


22 


North 


Shore 


25 


June 


15 


Sandy 


Island 


20 


July 


27 


Goose 


Islands 


25 


June 


22 


North 


Shore 


31 


June 


22 


North 


Shore 


23 


August 


17 


Goose 


Islands 


23 


July 


22 


North 


Shore 


25 


June 


22 


North 


Shore 


29 


June 


26 


North 


Shore 


22 


June 


22 


North 


Shore 


33 


June 


22 


North 


Shore 


48 


July 


21 


Sandy 


Island 


45 


August 


7 


Sandy 


Island 


46 


August 


7 


Goose 


Islands 


58 


June 


22 


Goose 


Islands 


59 


June 


1 


Sandy 


Island 


69 


July 


13 


Sandy 


Island 


50 


July 


27 


Goose 


Islands 


71 


June 


19 


North 


Shore 


73 


July 


13 


Sandy 


Island 


46 


August 


17 


Goose 


Islands 


92 


June 


26 


North 


Shore 


54 


June 


22 


Sandy 


Island 


67 


June 


15 


Sandy 


Island 


22 


July 


27 


North 


Shore 


16 


July 


21 


Sandy 


Island 


16 


August 


17 


Goose 


Island 



55 



GRAPH V 



AGE -LENGTH RELATIONSHIP 

FOR FEMALE STURGEON TAKEN BY 

COMMERCIAL POUNDS NETS IN LAKE 



NIPISSING IN 1970 




56 



Currier (1951) has suggested that the ray could be held in a vice 
for cutting. It was found that a preferable method was to make a shallow notch 
in the side of a piece of 2" x 4" lumber approximately 6" long. The open side 
of this notch was covered with a piece of slat secured with two bolts and wing 
nuts through both slat and block. With the wing nuts loosened, the ray was slipped 
into the groove with the butt and extending. The nuts were tightened and thus 
held the ray secure. A thin even slice was then cut by using the side of the 
block as a guide for the saw blade. Sections of fin ray approximately .5 
millimeter in thickness were quite easily cut with a jeweler's handsaw equipped 
with a 70 tooth-per-inch blade. These slices were taken as close to the butt or 
articulation to give as wide a section as possible. If slices were too thick, 
they were ground down between the finger tip and a sheet of emery paper. This was 
found to be unnecessary after some experience in obtaining a suitable thickness. 
Two or three sections were then laid out on a cellulose acetate slide (fish scale 
slide). Approximately 5 or 6 drops of acetone were spread over the sections and 
center of the slide with a pipette. Another slide was then placed over the 
sections and pressure put on directly over each section with the fingers to force 
the slides together and to distribute the acetone evenly. After thirty seconds to 
one minute, this resulted in a permanent study section (the acetone and/or the 
plastic penetrates the section to produce a better distinction of rings, i.e. 
annul i) . 

Alternate methods for mounting sections have been described by 
Currier (1951) where glass slides and glycerine, water, alcohol or Canadian balsam 
were used to coat sections for reading and by Pycha (1955) where the sections were 
cemented onto a slide and covered with glycerine after polishing. 

3 . Age Determinations 

Reading of the sections to determine age was done under a binocular 
microscope with a sub-stage light. The rings appeared alternately dark and light 
indicating summer and winter growth. 

Table IV shows the information for the 29 female and 3 male 
sturgeon collected from June to August of 1970. Information is listed in order of 
increasing age. 

Graph V shows the Length-Age relationship for the 29 females. As 
can be seen in Table V, this growth rate is likely much the same as in Lake 
Francis and greater than that in Lake Nipigon (although it is hard to compare as 
these lengths are fork lengths rather than total lengths) . A comparison of Table V 
and Graph VI shows that the weight-length relationship is also probably similar 
to Lake St. Francis. 



SUMMARY 

This report is a summary of all available records on the Lake 
Nipissing Sturgeon. 

There is little doubt in the minds of the authors that there have 
been drastic changes in the size and age structure of the population over the 
past half century (and most markedly over the last decade) . The causes for these 
changes may be due to any number of factors of which the following are considered 
most important: 

(1) Loss of Spawning Grounds--the Sturgeon River by all records 

57 



was the most important spawning ground. Wood fiber and pulp has been dumped into 
this river for nearly 50 years and the bottom is now completely covered with these 
wastes . 

(2) Fishing Pressure — from the 1960-63 tagging study, it was 
determined that sturgeon may move around to a much greater extent than had been 
thought when the commercial fishing limits were set up. Perhaps, most of the 
sturgeon in the lake are vulnerable to the fishery. (The original theory was that 
if all pound nets were restricted to a particular area of the lake, this would 
leave large areas available for sturgeon to reproduce and live unmolested by 
netting operations.) 

(3) Other Forms of Pollution- -since the sturgeon is a late 
maturing and long living fish, it may be more prone to pollution than other species 

(4) Prior to 1953, the season was closed for netting sturgeon 
during the month of June. Graph II iiidicates that approximately 25% of the harvest 
since 1953 has been in June. Therefore, it is possible that this extended season 
has affected the population of the lake, by increased harvests since that time 
(Graph I) . 



TABLE V 



SUMMARY OF THE GROWTH OF STURGEON BY FIVE YEAR PERIODS 

FOR LAKE ST. FRANCIS AND LAKE NIPIGON 
(FORK LENGTHS) (MacKAY, 1963) 



AGE 
COMPLETED 

YEARS 



GROWTH 



LENGTH (FORK) 


IN INCHES 


LAKE 


LAKE 


ST. FRANCIS 


NIPIGON 


0-20 


0-17 


20-29 


17-24 


29-35 


24-29 


35-40 


29-33 


40-45 


33-37 





WEIGHT 




IN POUNDS 




LAKE 




LAKE 


ST. FRANCIS 


NIPIGON 


0- 2 




0- 1 


2- 6 




1- 3 


6-12 




3- 5 


12-18 




5- 8 


18-36 




8-12 



0- 5 

5-10 

10-15 

15-20 

20-25 



FUTURE 



The Fisheries Management Unit plans to continue its lake sturgeon 
study. With the continued help of the commercial operators, it is hoped that 
more undersized fish will be tagged so as to study movements as well as to aid 

in estimating the population size. Also, the fishermen will be asked to continue 
to save fins and other information so that growth rates may be determined more 
accurately. Further, stomach contents and reproductive states will be analyzed. 

58 



GRAPH VI 



LENGTH -WEIGHT RELATIONSHIP 
FOR FEMALE STURGEON TAKEN BY 
COMMERCIAL POUND NETS IN LAKE 
NIPISSING IN 1970 



(n = 29) 



10 



20 30 

LENGTH (INCHES) 
59 



40 



50 



60 



70 



ACKNOWLEDGEMENTS 

The authors would like to thank Mr. Arthur Taillon for all his 
help in providing records as well as collecting information on his legal fish 
and tagging the undersized ones. Also, we would like to mention Mr. Gerald 
Blunt who was very helpful in preparing sections for aging, and Mr . C . Jorgensen, 
Project Biologist, for editing this report. 

REFERENCES 

Currier, J. P. 1951. The use of pectoral fin rays for determining the age of 
sturgeon and other species of fish. Reprint from Can. Fish 
Culturlist #11, Oct., 1951. 

Gage, J. F. 1960. The history of the spawning of the lake sturgeon in Lake 

Nipissing. Ont . Dept . of Lands and Forests (Unpublished Report). 

Harkness, W. J. K. 1936. Biological survey of Lake Nipissing. The North Bay 

Nugget, Friday, Jan. 24, 1936, to August 21, 1936 (every Friday). 

Harkness, W. J. K. and J. R. Dymond. 1961. The lake sturgeon. Department of 
Lands and Forests Publication. 117 pp. 

MacKay, H. H. 1936. Fishes of Ontario. Bryant Press, Toronto. 289 pp. 

Pycha, R. L. 1955. A quick method of preparing permanent fin-ray and spine 
sections. California Dept. of Fish and Game Bulletin. 



60 



REPRODUCTIVE CHARACTERISTICS 
OF THE PARRY SOUND DEER HERD 

by 

S. A. MUNROE, Deer Range Biologist 

ABSTRACT 



The initial stage of a long term study of the 
reproductive characteristics of the white-tailed 
deer, Odococoileus virginianus borealis Miller, 
herd of the Parry Sound District commenced in 1969 
Hunters were contacted in the field and by letter 
and asked for co-operation in collecting specimens 

A total of 48 pair and 14 single ovaries 
were turned into District staff. The age class 
distribution of the 62 does from which paired 
ovaries were taken was 9 fawns, 17 yearlings 
and 36 adults. Fifteen (38.5%) of 39 does, 1% 
years of age and older, had ovulated. Of these 
15 does, 4 or 10.3% had ovulated twice. The 
average number of estrus cycles per doe was 1.36. 

The mean ovulation rate of 1.60 was identical 
for the 10 adults and 5 yearlings. None of the 
fawns collected had ovulated. Since implantation 
does not occur until 30 days following conception, 
it was not possible to determine whether any of 
the does which had ovulated were pregnant . 

By aging all pigmented scars in the ovaries, 
the estimated conception rate for does in 1968 
was 1.82. There was no evidence to suggest that 
any of the 11 yearling does had conceived as 
fawns . 

All Graafian follicles 2 .0 mm and larger 
were counted. The mean number of follicles per 
fawn, yearling and adult does was 3.86, 5.46 
and 7.50 respectively. 

It is anticipated that sufficient data 
concerning fertilization rate, fetal rate and 
intra-uterine mortality can be obtained from 



61 



spring road fatalities so as to supplement 
the fall data in assessing the effects of range 
quality and weather severity on the condition 
of the deer herd in the Parry Sound District. 



INTRODUCTION 



It has been long since recognized from studies on domestic 
animals that reproductive rate is a proper assessment of an animal's overall 
condition. The condition of wild animals is dependent upon a number of environ- 
mental factors, notably proper nutrition, shelter requirements, and favourable 
weather conditions. The first important study concerning the relation of range 
conditions to the reproductive rate of the white-tailed deer was done in New 
York State in the late 1940 's (Cheatum and Severinghaus 1950). Studies of this 
nature have been expanded to cover a variety of cervids, but only one such study 
has been done on the white-tail in Ontario (Mansell 1967) . 

The deer population in the Parry Sound District and throughout 
the northern edge of the eastern deer range in Ontario dropped to critically 
low levels in the early 1960's following the two devastating winters of 1958-59 
and 1959-60. Deer numbers have risen again but not to the levels which existed 
in the 1940' s and 1950' s. The deer range was recognized as being in a deficient 
state largely through the large scale removal of existing deer shelter and the 
disappearance of available browse. A program to improve feeding conditions in 
the major deer yards in the Parry Sound District was begun in 1962, and was 
expanded in 1966-67 to include the entire deer range in eastern Ontario. As 
a result, the food supply has been considerably improved throughout large 
portions of the winter deer range. Deer managers are interested in the effect 
this deer range improvement had on the physical condition of our deer herds. 

A study was initiated in the fall of 1969 to assess the repro- 
ductive characteristics of the deer herds in the Parry Sound District . This 
study will be significant in the assessment of the physical conditions of our 
deer herd as they are affected by weather severity and improved food conditions. 

METHODS 

A printed circular which included a brief description of the 
proposed study, a diagram showing the female reproductive tract with instructions 
for its removal was sent to the secretary of 1,098 organized hunting groups in 
the District . During the weekend prior to and during the early part of the 1969 
hunting season (November 3-15) field staff contacted as many of the accessible 
hunting parties as possible to further describe and stimulate interest in this 
study. All parties checking through the Pakesley check station were similarly 
contacted. Several two-quart sized plastic freezer bags, ties and linen tags 
were distributed to the parties contacted. Specimens were gathered from the 
hunt camps by the field staff engaged in aging deer. Whenever possible the 
specimens were labelled as to Township, date shot and age. Aging was done by 
using the method of teeth wear and replacement adopted from Severinghaus (1949) . 
Upon collection, the plastic bag containing the reproductive material was perfora^ 
ted and immersed in a large jar containing 10% formalin. Some of the specimens 
were frozen then and fixed in the formalin. 



62 



In the laboratory, the reproductive tract (or part thereof) was 
removed from the fixed material and then allowed to fix for approximately one 
month before any analysis was made. During analysis the ovaries were removed 
and trimmed of all extraneous material, then a length and width measurement 
taken. Each ovary was hand-sliced with a sharp scalpel into a number of sagittal 
sections 1-2 mm thick. Each section was macroscopically examined for rupture 
sites, corpora lutea, corpora albicantia (also called degenerating corpora lutea 
of pregnancy) and large Graafian follicles. A measurement was taken of the maximum 
diameters (at right angles) of all corpora and Graafian follicles larger than 
2.0 mm. Following this analysis, all ovaries were weighed. 

RESULTS 

1 . Collection of Reproductive Tracts 

Approximately 80 donations of reproductive material were turned 
into District field staff during the 1969 hunting season. Including one road 
injured doe collected in September, ovaries were collected from 62 deer. This 
sample included 48 pair and 14 single ovaries. The age class distribution of 
these 62 females was 9 fawns, 17 yearlings and 36 adults. 

Ovary weight, length and width measurements were averaged for 
each age class (Table I) to facilitate placing unaged deer into the above three 
broad age classes. 

For most of the following analysis, only pairs of ovaries were 
considered when interpreting results. 

2 . Ovarian Analysis 

The Ovarian Cycle : Through a combination of endogenous and 
exogenous stimuli, follicular development within the ovary of the white-tailed 
deer commences early in the autumn and progresses until late October to early 
November when adult does in this area experience their initial period of estrus. 
This is followed 24 to 36 hours later by the spontaneous release of an ovum 
from the Graafian follicle and its eventual entry into the fallopian tube 
(Cheatum 1949). Following rupture, cellular material derived from the granulosa 
cells lining the follicle cavity permeates the empty follicle. The body which 
forms from this cellular proliferation is called a corpus luteum of estrus. This 
corpus luteum functions as an endocrine gland, secreting the hormone progesterone 
which arrests further follicular development and prepares the lining of the uterus 
for implantation of the blastocyst (Nalbandov 1964). If the ovum is fertilized, 
the corpus luteum of estrus becomes a corpus luteum of pregnancy and remains in 
the ovary until parturition after which it begins to degenerate. Upon degenera- 
tion, the lutein cells become pigmented, causing the degenerating corpus luteum 
of pregnancy to take on a pigmented appearance. These pigmented structures are 
called corpora albicantia or degenerating corpora lutea of pregnancy. 

If the released ovum is not fertilized, the corpus luteum of 
estrus undergoes degeneration 14 to 15 days following estrus and is termed a 
degenerating corpus luteum of estrus. Follicular development recurs and another 
estrus cycle follows the initial cycle by approximately 28 days (Cheatum 1949) . 



63 








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64 





3 . Types of Pigmented Structures 

Gibson (1957) described the occurrence of six types of pigmented 
scars in the ovaries of deer collected in eastern Ontario: current and degenerating 
corpora lutea of estrus; current and degenerating corpora lutea of pregnancy (the 
latter will be termed corpora albicantia in this report; accessory corpora lutea and 
corpora lutea aberrons. 

Only current corpora lutea of estrus, degenerating corpora lutea 
of estrus and corpora albicantia have been recognized to date in this macroscopic 
examination of deer ovaries. It is likely that some of the current corpora lutea 
of estrus were in fact current corpora lutea of pregnancy, but since implantation 
had not occurred, this could not be substantiated. According to Armstrong (1950), 
a deer is not recognizably pregnant until 30 days following fertilization. 

The only reproductive history that can be followed with the data 
at hand is: follicular development, ovulation rate, estrus cycles and estimated 
conception rate of the previous breeding season. 

4. Period of Estrus and Ovulation Rate 

Ovaries taken from the 62 does collected in 1969 are broken down 
in Table II by age class to show ovulation incidence. 

Each corpus luteum of estrus was determined to be either current 
or degenerating on the basis of size, shape and colour. Degenerating corpora 
lutea of estrus are smaller with generally an irregular outline, and have a 
creamy white colour. The mean size of 24 current corpora lutea of estrus was 
4.86 mm x 4.24 mm compared to 3.89 mm x 3.05 mm as the mean size of 9 degenerating 
corpora lutea of estrus. 

The 15 does which possessed corpora lutea of estrus had experi- 
enced 19 estrus cycles, or 1.36 per doe. Since some of these females which had 
experienced one estrus cycle, were about to ovulate for a second time, the average 
number of estrus cycles per doe would actually have been greater than 1.36. 

An estimated date of estrus (October or early November) was 
assigned to each doe which had experienced either a first or a second estrus 
cycle. Ten of the 19 estrus periods (52.7%) occurred sometime in October while 
the remaining 9 (47.3%) took place sometime during the first week of the hunting 
season. One adult doe collected on September 8 had two large Graafian follicles 
measuring 4.5 mm and 4.0 mm at their widest diameter. The presence of these 
large follicles suggests that this doe would have come into its first cycle of 
estrus sometime early in October. 

Almost 407o of the sample of adult does collected during the 
hunting season had ovulated at least once, while 10.57 o had ovulated twice (Table 
II). None of the fawns collected had ovulated. The presence of a large follicle 
in the ovaries of three fawns suggested that ovulation would have occurred late 
in November or simetime in December. 

An age class frequency distribution of current and degenerating 
corpora lutea of estrus is presented in Table III. Only those corpora from an 
earlier estrus cycle are called degenerating corpora lutea of estrus. 



65 



TABLE II 



AGE CLASS DISTRIBUTION AND OVULATION INCIDENCE 
OF THE 62 DEER EXAMINED DURING THE 1969 HUNTING SEASON 



IN THE PARRY SOUND DISTRICT 





























NO. OF 




NO. 


% 




NO 


. OF 


NO. 


AGE OVARY PAIRS 


OVULATED 


OVULATED 


OVARY 


SINGLE 


OVULATED 


Fawns 


8 









0.0 






1 









1% 


11 






5 


45.5 






6 









2% 


1 






1 


100.0 






1 









3% 


8 






4 


50.0 






2 









4% 


4 






2 


50.0 






1 









5% 


3 









0.0 






1 






1 


6% 


2 









0.0 






1 









Unaged 


11 






3 


27.3 






1 













NO. OF 






NO. OVULATED 










AT LEAST 












AGE 




OVARY PAIRS 




ONCE 


% 




TWICE 


7o 




Fawns 






8 






















Yearlings 






11 




5 


45.5 






1 


9 


.1 


Adults* 






28 




10 


35.7 






3 


10 


.7 


Total Adult; 






39 




15 


38.5 






4 


10 


.3 



* One female collected on September 8, 1969, was eliminated from this sample. 

In the females examined with paired ovaries, the mean ovulation 
rate for the 5 yearlings and 10 adults was identical at 1.60 (Table III). Adults, 
however, had a greater tendency to shed two ova than did yearlings, suggesting 
that adults are more prolific than yearlings. 

Among the 4 does which had experienced a second estrus cycle, the 
ovulation rate of the first cycle (2.25) was greater than that of the second (1.75) 



66 



TABLE III 



AGE CLASS FREQUENCY DISTRIBUTION OF CURRENT AND DEGENERATING 
CORPORA LUTEA OF ESTRUS IN 15 DOES COLLECTED 
DURING THE 1969 HUNTING SEASON 
IN THE PARRY SOUND DISTRICT 



1. CURRENT CORPORA LUTEA OF ESTRUS 



AGE 


SAMPLE 




SIZE 


Fawns 


7 


Ik 


5 


Adults 


10 


Total 




Adults 


15 



NO. OF CORPORA LUTEA 



SUM 



MEAN 



16 



24 



0.0 

1.60 

1.60 

1.60 



2. DEGENERATING CORPORA LUTEA OF ESTRUS* 



AGE 



SAMPLE 
SIZE 



NO. OF CORPORA LUTEA 



SUM 



MEAN 



1% 

Adults 

Total 
Adults 



2.00 
2.33 



4 3 1 9 2.25 

* Counted only in does in which two generations of corpora lutea have occurred. 



5 . Estimates of the 1968 Conception Rate 

Cheatum (1949) suggested that the conception rate of the previous 
breeding season can be determined by counting the large pigmented scars (corpora 
albicantia) on the ovaries collected during the fall and winter period. Mansell 
(1967) distinguished corpora albicantia 6-months-old from those 18-months-old on 
the basis of size. He found that the average size of those 6-months-old scars 
was 2.13 mm x 1.25 mm and the average size of those 18-months-old was 1.25 mm x 
0.61 mm. Gibson (1957) suggests that scars 18-months of age and older persist in 
the ovary relatively unchanged in size. 

67 



It was generally quite difficult to age these pigmented scars on 
a size basis alone. Since cellular features were not examined microscopically, 
other criteria such as general appearance, position in the ovary and existance of 
rupture points were relied upon to help age these structures. 

The age class frequency distribution of these two age classifi- 
cations of corpora albicantia is presented in Table IV. 

The mean number of 6-month-old corpora albicantia for adult does 
was 1.82. This figure represents an estimation of last year's production and is 
12.1% greater than the current rate of ovulation. There is no evidence from the 
sample of 11 pair of yearling ovaries that they had conceived as fawns. 

The largest number of pigmented scars found in any one doe was 
10, counted on the ovaries of a 6% year old. Mansell (1967) counted 11 pigmented 
scars on a 14-year-old doe shot on the Bruce Peninsula. Both Mansell (1967) for 
the white-tailed deer and Simkin (1965) for moose ( Alces alces ) found a high 
correlation between the age of the animal and the number of pigmented scars. Their 
findings suggested the value of these ovarian scars in estimating past productivity 

An example of the difficulty involved in aging scars is given as 
follows: One 5^ year-old had a total of 8 pigmented scars on her ovaries. The 
measurements of these are: (1) 3.1 mm x 1.5 mm; (2) 2.5 mm x 1.0 mm; (3) 2 .0 mm x 
2.0 mm; (4) 2.0 mm x 1.0 mm; (5) 1.0 mm x 1.0 mm; (6) 1.2 mm x 0.7 mm; (7) 1.0 mm 
x 0.4 mm; (8) 1.0 mm x 0.3 mm. Based on the identification criteria previously 
established, the first four scars were aged as 6-months of age, indicating this 
female has conceived four young as a 4% year old. Such multiple conceptions are 
possible but rare. 

The mean size of 64 acres identified as 6-month-old corpora 
albicantia in all ovaries examined was 2.38 mm x 1.30 mm as compared to 1.28 mm x 
0.75 mm as the mean size for 44 corpora albicantia 18-months-old and older. 

6. Follicular Development 

An age class frequency distribution for all follicles in three 
size categories 2.0-3.0 mm, 3.1-4.9 mm and 5.0 mm + from all ovary pairs is 
presented in Table V. Adults as expected produced a significantly greater (P<0.01) 
number of follicles per doe than did yearlings and does. Yearlings produced a 
greater number of follicles than fawns, but the difference was not significant. 
The mean number of follicles 5.0 mm in diameter and larger (which were considered 
to be potential corpora lutea of estrus) was 0.28, 0.73 and 1.07 for fawns, 
yearlings and adults respectively. 

DISCUSSION 

1 . The Breeding Season 

Based on the limited evidence on hand it appears that most 
female deer reach peak breeding condition for the first or second time during 
late October or early November in the Parry Sound District. A sample of aged 
embryos is necessary to make more precise statements concerning the onset of 
breeding. Mansell (1967) determined by backdating fetal ages that adult does 
conceived around November 20 on the Bruce Penninsula . He found that peak breeding 
time for juveniles occurred about three weeks later. 

68 



TABLE IV 



AGE CLASS FREQUENCY DISTRIBUTION OF CORPORA ALBICANTIA 
FROM DOES COLLECTED DURING THE 1969 HUNTING SEASON 



1. 6 -MONTHS -OLD 



IN THE PARRY SOUND DISTRICT 



AGE 



SAMPLE 
SIZE 



NO. OF CORPORA ALBICANTIA 



SUM 



MEAN 



5% 



Unaged 

Total 
Adults 
(2% +) 



11 
1 
8 
4 
3 
2 

10 

28 



11 



10 



5 
2 

1 
3 

11 






0.00 


1 


1.00 


15 


1.87 


8 


2.00 


10 


3.33 


5 


2.50 


12 


1.20 



51 



1.82 



2. 18 -MONTHS -OLD AND OLDER 



AGE 



SAMPLE 
SIZE 







NO. OF CORPORA ALBICANTIA 



4 



SUM 



MEAN 



1% 
2% 

2k 

4% 
5% 



Unaged 

Total 
Adults 
Oh +) 



11 
1 
3 
2 
3 
2 
4 

14 



11 




4 5 3 1 
69 






0.00 





0.00 


7 


2.33 


2 


1.00 


7 


2.33 


12 


6.00 


10 


2.50 



38 



2.71 



TABLE V 



AGE CLASS DISTRIBUTION OF THREE SIZE CLASSES OF FOLLICLES 

FOUND IN DOES SHOT DURING THE 1969 HUNTING SEASON 

IN PARRY SOUND DISTRICT 



AGE 



SAMPLE 
SIZE 



NO. OF FOLLICLES /SIZE CLASS 



2 .0 - 3 .0 mm 



3.1 - 4.9 mm 



5 .0 + mm 



SUM 



MEAN 



Fawns 8 

Yearlings 11 

Adults 29 



22 

43 
149 



6 
9 

34 



2 30 3.75 

8 60 5.46 

31 214 7.38 



2 . Factors Affecting Reproduction 

It has been found that the reproductive rate of the white-tailed 
deer increases with increasing age. The data to date infers that fawns play a 
negligable role in the productivity of the deer herd in this area. None of the 
fawns examined had ovulated and none of the yearlings had conceived as fawns. 

Mansell (1967) found that almost 10% of the fawns had ovulated 
in early November on the Bruce Penninsula, and 15% of the yearlings conceived as 
fawns. Severinghaus and Cheatum (1950) reported that up to 40% of female fawns 
reach sexual maturity on high quality deer range. 

Table VI shows the comparison of ovulation rates for three age 
classes of white-tailed deer throughout its range. The fact that fawns add little 
to herd productivity on the more northern range is consistent with the harsh 
environmental conditions that prevail in the northern front of the deer range. 

The early results from this study failed to show any difference 
between adult and yearling ovulation rate. Sample size is, however, quite small. 
As Table VI suggests, the ovulation rate of adults is appreciably larger than 
yearlings and fawns respectively. The mean ovulation rate of 1.60 for adults 
compares favourably with the figure of 1.62 which Mansell (1967) found for adult 
does on the Bruce Peninsula. Both these figures fit into the scheme in Table VI 
where ovulation rates decrease with increasing latitude. This is reverse to the 
situation which exists for some small mammals. Snowshoe hares, Lepus americanus , 
(Keith, Rongstad and Meslow 1966) have greater rates of ovulation in the higher 
latitudes, a factor reflecting their excellent adaptation to the northern areas. 

There is a possibility that the reproductive rate of yearling does 
is a good indicator of range quality. Fawns tend to suffer more physically from 
inadequate winter habitat; and improper range combined with a harsh climate could 
cause a delay in their reaching sexual maturity, a factor which could alter their 
rate of ovulation. Robinette, Gashwiler, Jones and Crane (1955) consider summer 
range condition is of far greater importance in determining the reproductive rate 



70 



of older mule deer ( Odocoileus hemionus hemionus ), while for yearlings, both 
summer and winter range may be of equal importance. Julander, Robinette and 
Jones (1961) found that the ovulation rate of female mule deer on good summer 
range was 50% greater than for does on poor summer range. Verme (1962) points 
out that "white-tail doe fawns that had been severely underfed over winter 
achieved average reproductive success the following autumn--as yearlings—pro- 
vided they obtained proper nourishment throughout the intervening months." Verme 
strongly suggests the value of the total environment rather than only winter 
range on the reproduction of northern white-tails. 

The production of large graafian follicles from primary follicles 
is under the influence of follicle stimulating hormone (FSH) produced by the 
anterior hypophysis (Nalbandov 1964) . The level of endocrine production is 
influenced by nutrition. It is reasonable to suggest that the level of follicle 
development in white-tail ovaries collected in the fall is indicative of the con- 
dition of the deer following the yarding period and the quality of its summer 
range. The mean number of follicles was 3.75, 5.46 and 7.38 for fawns, yearlings 
and adults respectively. Mansell (1967) found the average number of follicles 
to be 5.80, 6.61 and 10.10 for fawns, yearlings and adults respectively on the 
Bruce Peninsula . 



TABLE VI 



COMPARISON OF OVULATION RATES IN WHITE -TAILED DEER BY LATITUDE 



AREA 



FAWNS 



OVULATION RATE 



YEARLINGS 



ADULTS 



Southern Range 




Iowa 


1.09 


North Dakota 


0.00 


Texas 


1.00 


Northern Range 




Massachusetts 


1.06 


Maine 


1.38 


Michigan 


0.83 


Manitoba 


0.00 



2.15 
1.50 
1.27 



1.80 
1.58 
2.10 
1.22 



2.28 
2.26 
1.52 



2.04 
1.79 
2.26 
1.92 



Ontario (Bruce 
Peninsula) 



0.09 



1.25 



1.62 



Ontario 
(Parry Sound) 



0.00 



1.60 



1.60 



71 



3 . Study of Limitations 

The hunting season is the most advantageous time to collect 
information on the reproductive characteristics of a white-tailed deer herd, for 
we can depend upon the assistance of hunters. However, this is not the most 
instructive period to gather this data. With the hunting season in early November 
only some of the does have ovulated, and for those which have ovulated we cannot 
determine whether they are pregnant or not. Thus no information is available on 
fertilization and fetal rates, or the extent of intra-uterine mortality; the 
latter being very important in assessing winter range quality and weather severity 
on reproductive success. 

Since we are using a straight-forward field technique to evaluate 
reproductive characteristics, we are subject to a number of sources of error. 
There is the possibility of mistaking the identity of certain ovarian structures 
without the use of a stain. Rupture sites may be obliterated during the slicing 
process. Since some of the material may not be fixed for several days or even a 
week following collection, tissue decay may result in a difficulty in structure 
identification. Another possibility of error is the presence of polyovular folli- 
cles. Gibson (1957) points out the varity of this phenomenon. 

A major limiting factor is the possibility of improperly aging 
corpora albicantia. Such can lead to overestimating the productivity of the 
previous breeding season. In this study, the mean number of 6-month-old corpora 
albicantia for 28 adult does was 1.82. This is 12.1% higher than the 1969 ovula- 
tion rate of 1.60 for 10 adult and 5 yearling does. Golley (1957) found corpora 
albicantia counts (1.74) to be 18% higher than the current ovulation rate (1.47) 
in the black-tailed deer ( Odocoileus hemionus columbianus ) . He suggests that 
corpora albicantia can theoretically rise from sources other than corpora lutea 
of pregnancy. There is a possibility that pigmented accessory corpora lutea are 
being counted as corpora albicantia. According to Golley (1957) these accessory 
structures develop through the luteinization of un-ruptured follicles, and remain 
in the ovary along with a corpus luteum of pregnancy, and degenerates with it. If 
these accessory corpora become pigmented in the white-tailed deer, they may be 
large enough to be counted as 6-month-old corpora albicantia, and would lead to an 
overestimation of past conception rates. Mansell (1967) identified 31 accessory 
corpora lutea in ovaries which contained 32 corpora lutea of pregnancy. He found 
that these accessory corpora lutea were much smaller than the corpora lutea of 
pregnancy. Mansell's (1967) estimate of the fetal rate of 1.40 based on corpora 
albicantia counts did not differ greatly from the fetal rate of 1.36 based on 
fetal counts from 22 does collected on the Bruce Peninsula . 



CONCLUSIONS 

The support provided by hunters to make this study possible was 
very encouraging. Since no rewards were offered, hunters made an effort to collect 
the specimens as their contribution to proper deer management. Increased hunter 
participation is anticipated as the study continues. With further experience, the 
macroscopic field technique should prove adequate for a study of this type. Some 
specimens should be microscopically analyzed to complement the macroscopic work. 

It is hoped that sufficient information can be collected from 
road casualties in the spring to supplement the fall data. Over a number of 
years we should then have another significant bio-assay of the effects of the 
effects of the deer management program on the condition of deer in the Parry 
Sound District . 

72 



ACKNOWLEDGEMENTS 

I gratefully acknowledge the assistance of all hunters who 
took the effort to remove the reproductive material. To all District staff who 
participated in the collection of the specimens, I am indebted. I am extremely- 
grateful to my supervisor Carman Douglas who offered helpful suggestions in 
preparing the study and reviewing the paper. Thanks also goes to John Macfie 
for his helpful criticism on the paper preparation. I wish to thank Dan Mansell 
of the Lake Huron District for his help in identification of ovarian structures. 

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73